Cold Start Up & Codes P0300, P1416, P1683

[ChrisWS6]

My check engine light came on one night even though it was running fine, then the car was shut off for a couple hours and when starting it back up it was hesitant to start. It would start, then die out. I took it to Auto Zone and the only code that showed was P1416. Then the care wouldn't start up when it was cold out. I told it to a mechanic who said it's probably the spark plugs and that's what they suggest to replace. I was going to take it back to have them replace them, then a friend said asked another mechanic who said that wouldn't be it since it only has 50,000 miles on it. So I took it to that mechanic who looked at it and he said 3 codes came up, P0300, P1416 & P1683. He advised me to put a can of Seafoam in the gas tank, which I did. Big mistake, I use to get 220 mpg and since using the Seafoam I only get 120 mpg. I took it back to that mechanic and said it still doesn't start up when it's cold and now the mpg went way down, which he said that's never happened to any vehicle he's used it in and asked if I was sure, as if I don't know that I'm getting almost half the miles to a tank of gas. Then he said to just get rid of the car, they're too much of a pain to work on and he doesn't even like messing with them. He even said the code P1683 has never come up on any vehicle he's worked on and he tried looking it up but couldn't find anything about that code.
I've read about code P1416 and how that can be looked at, but if anyone has info that might help a mechanic (if I find one who might know how to work on cars since it seems impossible around here), please let me know. Should I let the one place start with replacing spark plugs and maybe the fuel filter since I've read the Seafoam could have caused a problem with the filter? Any tips would be appreciated, I'd like to get it fixed and put away for the winter, especially if it's messing anything up driving it when it is warmer out.
Thanks.

[Naaman]

The P0300 means you "may" have multiple misfires. However, since you also have the secondary air injection code (P1416), it could be something other than a misfire. Also, the P1683 indicates that the computer is confused about the throttle for some reason.

If you're having hard starts, it may have to do with the air fuel mixture being incorrect.

What we know is that there is too much "stuff" coming out of the combustion chamber in the exhaust. Too many hydrocarbons, basically (you're not getting complete combustion). This could be due to a weak/absent spark, but it could also be due to a malfunctioning fuel injector (or more than one).

The secondary air system feeds oxygen into the exhaust stream to help the catalytic converters do a better job. Can't be sure if that system is the one malfunctioning, but the codes suggest that it is a possibility.

What kind of car is this? If it's an F-body, the 50,000 miles things is irrelevant: the car (and presumably plugs, if they are original... your post makes me think they are) are way old. They should be replaced, IMO.

And that mechanic you talked to is a waste of your time. Don't give him a dime of your money.

Anyway, if you think you've ruined the fuel filter, change it (how old is it, anyway?) I'd also have the plugs changed: it's likely they are fouled even if they aren't otherwise malfunctioning. Since my best guess is that whatever IS wrong with your car WILL require you to change those things, just get them done and see if the problem goes away. But also, I'd recommend having your injectors tested as well.

[SMWS6TA]

Seafoam is one of those things of a last resort for me. Yeah it can "clean" a system out but all that crap goes somewhere..

I would not have done it on new plugs and if you have bad enough trash in the system it could also kill the O2 sensors.

The Throttle Position sensor may just need to be reset.

Weak start up - 3 things to check, always are fuel, air, spark.

Fuel - filter clean (how old is it?), bad fuel?, weak oe going bad fuel pump/regulator, fuel injector failure/clog? Check fuel pressure at the rail? Should be at 56psi and hold, if it starts to drop then you have a small crack in the hard plastic fuel line in the tank that the fuel flows from the pump to the fuel lines.

Air - air filter, Throttle Body blade opening? MAF screen clean?, Idle Air sensor working and not clogged?

Spark - wires and plugs. if you had a single code like P0304 (the last digit is the cylinder) etc I would say switch the plug with another and see if it follows, if not, then switch the wire, does it follow?, Lastly the coil. If it does follow after each change thenyou know what the issue is on that cylinder.




Dropping half you fuel would mean could be MAF issue, flooding from a bad injector and it not burning off, bad plugs.

Disconnect the plug wires and turn it over a few seconds like 20-30. Pull a few plugs an see how wet they are. They should be a little but if one's dripping wet you might have an injector issue.

[pajeff02]

Subscribed to see where this goes.

OP - let us know what you find and if additional assistance is needed.

[ChrisWS6]

Thanks Naaman & SMWS6TA for the tips on what may be the cause of this.

I spoke to another mechanic today that someone recommended and he is willing to take a look at it, so once the weather warms up a bit, I will be taking it there.

Since it is an '02 WS-6 and the plugs have never been changed, I'm going to have him do replace them along with the fuel filter, even though some mechanics say the plugs don't need to be done until 100k miles, they probably need it being they're so old.

I will update here when/if it gets fixed. Thanks again!

[The Guz]

I have been fighting a P0300 for months now and I have never figured out what it is.

I changed the plugs, wires, fuel filter and 02 sensors. I even bought one new coil to move it around and there is still a misfire. I see it when I scan it with HP Tuners. I don't drive it that much so I don't know if one of the injectors is plugged or the cam position sensor went bad.

[35th-ANV-SS]

Where in Indiana are you? Fellow Hoosier here.

[pajeff02]

Thanks Naaman & SMWS6TA for the tips on what may be the cause of this.

I spoke to another mechanic today that someone recommended and he is willing to take a look at it, so once the weather warms up a bit, I will be taking it there.

Since it is an '02 WS-6 and the plugs have never been changed, I'm going to have him do replace them along with the fuel filter, even though some mechanics say the plugs don't need to be done until 100k miles, they probably need it being they're so old.

I will update here when/if it gets fixed. Thanks again!

The AC Delco Iridiums are in fact "100,000 mile plugs". I changed ours at around 72,000 miles in the Trans Am and up over 90,000 miles in our Suburban and they looked great in both instances. Most people switch over to NGK TR55 plugs, but for a few more bucks you can throw Iridiums back in it. I think that the part numbers for them have changed in recent years...

[SMWS6TA]

I remember back in the days of Sarge of the spark plug debates.

Basically copper plugs are hotter and quicker to spark but have a short life 25k-30k miles. Less if you run Nitrous.
Next Iridium's - are between copper and platinum. They are hotter than platinum but last much longer then platinum or cooper, truly a 100k mile plug.
Platinum's - these came out in the late 80's-90's, they gave better life than copper but not as hot as cooper in spark. Usually last around 40-50k miles.


Most track guys prefer the copper because the cost and hotter/quicker spark. When you literally can burn a set of plugs per run it gets expensive quick if you use the other two.


For my daily vehicles I use the Iridium's but on my bird I use NGK TR-6's.

For stock to mild bolt on's for LS1/2's the TR-55's are great. If you want Iridium they are TR-5's for NGK.

[Naaman]

I like the TR5 better than the TR55s. People don't seem to believe me, but the TR5s actually improved my fuel economy by about 30-40 miles per full tank. For comparison, the plugs they replaced were Autolites. I now have some copper TR6s in there, but I can't compare because it's a different engine than the one that had the iridium IX plugs.

[35th-ANV-SS]

Autolite plugs are junk.

Sent from my SM-G900V using Tapatalk

[pajeff02]

I was never a fan of Champion.

Have never had an issue with AC Delco, NGK or Bosch spark plugs, so I tend to go with these brands in our cars.

[ChrisWS6]

Update – I’ve taken my car to 3 mechanics in the past year trying to get this problem fixed, the 1st one said since no codes were coming up it could just be the age of the car. He didn't recommend anything to fix the problem of it not starting up when it’s cold out.

In July I took it to another mechanic who changed the fuel filter who said that should fix it but that didn't help it.

I was then told about a great mechanic an hour away who owns a couple TA’s and only works on these type of cars and decided to take it to him.

My cars been there for 12 days and that day the guy told my friend and I that he won’t do anything to the car until letting me know what’s wrong and giving me a price. After 4 days I called to see if he found anything out. He asked if I’ve been using the same ignition key, I said usually. He said that is the problem with it not starting up, the computer is getting messed if I don’t use the same key. I told him both keys have been used in the past 15 years and it never caused a problem. He swore that’s the problem and to fix it costs a lot of money but he can put a switch on it under the dash for $1.50 & it won’t mess anything up.

After calling him for 4 days and finally him answering, I said I'd be coming to get the car. He said they’re waiting on some parts. I asked what he meant since he told me it was a $1.50 switch. He then said they replaced the starter, ignition and the water pump is off the car and it should be coming in by 3:00 that day. I asked what happened to the many times he said nothing would be fixed until he let me know if anything was found wrong and the cost. He apologized and said he forgot and just told them to fix it. I couldn’t understand him when he kept saying them, come to find out, he’s not a mechanic, his friend is and my car has been at his friends place for the past 2 weeks.

Now I’m told by a couple people I've asked about this that it probably wasn't the starter since it only had a problem starting up when it was cold. I never told this guy to do these repairs and it's fine if it was needed and it's has been replaced, but it hard to trust him since there were so many lies thought the 3 times of talking to him.

Can anyone tell me if a starter and ignition could cause problems only when it’s cold out? Also, does it sound right that using either of the keys that were made for the car when buying it new would mess up the computer? Any comments of maybe what I should expect to be charged (approx.) for a starter, ignition, water pump? I don’t even know what to do when going to get my car, I’m afraid that this guy is going to give me a bill of a $1k when they didn't change any parts. Thanks

[Redphoenix1998]

Hey there just chiming in. Starter and ignition will not cause the problem. From your original post I'm focusing more on the p1416 and the p0300. P1416 is the secondary air injection system on bank 2. What that means is the check valve may be stuck open due to carbon buildup. It is common since the check valve resides on the header itself. When that happens all types of bad things can happen. I'll bet your bank 2 injectors are fouled out because your computer was compensating for the excess air being injected into the exhaust stream being read by your O2 sensor hence telling the computer bank 2 is lean and to give it more fuel. More fuel meaning harder start because you are flooding the cylinder with more fuel than air. Seafoam will not fix it. Waterpump, VATS bypass, key, are not symptoms. The parts that I would be concerned with are the following:
Secondary air check valve bank 2- suspected culprit
Plugs- Fouled out from too much fuel
O2 Sensors- leaned out and usually at 100k you should replace all 4 to keep in fuel control
Catalytic converter- Misfires are bad and excess fuel is bad for the cat. It may be shot. Unless you throw a P0420 i wouldn't worry too much about this but if you do you should replace the cat.

Possible things to try to do to fix the problem itself. Disconnect the secondary air check valve from the header. Change your plugs, they're due anyways. See if the car hard starts. Hope that helped.

[Redphoenix1998]

Also as SMWS6TA said above

Spark, Air, Fuel!

Every good mechanic and diagnostician knows this. In your case it starts indirectly with air possibly causing you an issue. Air only injected into bank 2 will cause a P0300 because you have 4 cylinders out of 8 misfiring. You won't get a dedicated P0302 or P0304 because it is multiple cylinders across the same bike misfiring because of the excess fuel being dumped because your O2's are out of range due to extra air being pumped in to give it false readings. That's the flow I see in my head and where I would start for sure if I had to work on your car. But from a mechanic to a customer, I apologize for your bad experiences. Too many guys watch youtube on how to fix cars and think they know how to do it after a few videos!

[ChrisWS6]

Thank you for posting your comments, it’d be nice if I could find mechanics like you and others who know what they’re talking about. If I don’t get rid of the car since it’s costing too much money trying to get it fixed, I’ll be sure the next mechanic checks the issues you listed before doing anything else.

I did get my car last night and left it outside overnight to see if it would start this morning, but it doesn’t. So you are correct, the starter won’t fix the problem.

My attorney told me not to pay the guy when picking the car up and if the guy refused to let me take it, leave and call the police. I’ve never done that and felt bad, but the guy was ok with me saying I’ll send him the money tomorrow after having it looked at. When he handed me the detailed invoice (as he called it), it was a blank piece of paper with no company name, his name or anything printed as usual, only his writing of parts and labor with a total of $686. Then he told me there was warranties on the parts, which it's obvious by the invoice they most likely wouldn't do anything if the parts go bad since I wouldn't be able to prove who did the work since I'm paying someone else and not the dealership the guy took it to. Also, the ignition wasn't listed and when asking about it he said they weren’t able to change it since GM doesn’t let them make a new key, another lie he told me yesterday. When leaving his house, he called but my phone goes out of range in his area so his message came through 15 minutes later. He was yelling at me and saying I ignored his call and if the check isn’t overnighted within the next hour, he will come find me and my car.

Now I get to wait for more threats until talking to the lawyer who said I have enough proof that he failed to give me notice of fixing anything besides the $1.50 part and labor. I’d rather just pay it and not have to worry about this guy since my life is more important even though it gets old paying for nothing to be fixed.

Thanks again for the replies!

[Naaman]

Ugh... Sorry to hear about all this.

You said that it has a hard time starting when cold. Have you had the battery looked at? Batteries do go bad over time. Just had to replace mine a couple weeks ago. I thought that it was my alternator, but when I swapped the battery out, problem solved.

As for your other codes, I'm sorry to hear about all the hassle. Your story is exactly why I started doing as much as I can on my own. It's a headache, for sure, but one that comes with peace of mind and no legal battles if things go wrong.

[ChrisWS6]

Yes, I did replace the battery within the past 2 months. Thanks.

[ChrisWS6]

My car had work done recently and now code P1637 comes up and the check gauge light flashes on and off at random times. I tried finding info here and saw on another post the code could be the alternator.

A couple weeks ago there was a burning smell and had Auto Zone test it but no codes came up. Alternator went out next day so took it to mechanic and he replaced alternator, rack & pinion, tie rod end and power steering pump.

When driving home after it was repaired, the check gauge light was coming on and off and next morning bunch of antifreeze leaked. Took it back to mechanic on Friday but he didn’t see a leak and since the check gauge light wasn’t on when he started it, he said not sure why it’s coming on.

Had car tested today at O’Reilly’s and code P1637 is showing. Can anyone tell me if it might have to do with the alternator being replaced since it never showed up before? Also, any opinions about if I should go back to this mechanic or try another one? I paid him over $2,000 and being told not to go back since both times he replaced parts there's new problems right away.

[SMWS6TA]

A lot of times with an alternator swap the exciter wire (the thin wire) that connects to it gets broken or pulled out. Especially if someone forgets and pulls/drops the alternator without disconnecting it.


This should help if it's broken.

http://www.ls1.com/forums/f6/fix-if-...re-plu-133361/