Car not running right after header install

**Corvettekid82** · 07-05-2007, 03:08 PM

Okay, so I know there are quite a few threads like this and I have searched for the codes and such but I'd like to get everyones opinions. Heres the deal: Installed Pacesetter LTs and custom X-pipe setup. Reused stock O2s and just extended the wiring. Everything ran fine for about 250 miles. Out of nowhere it decides to bog on me and try to die while running and gives me a flashing SES. No issues on start up, but does not hold idle well. Scanned codes and got

P0300 Engine Misfire Detected
P0140 HO2S Circuit Insufficient Activity Bank 1 Sensor 2
P0155 HO2S Heater Performance Bank 2 Sensor 1
P0160 HO2S Circuit Insufficient Activity Bank 2 Sensor 2
P0418 Secondary Air Injection (AIR) Pump Relay Control Circuit Bank 1
P0412 Secondary Air Injection (AIR) Solenoid Relay Control Circuit Bank 1

Car has not had any tuning yet. Im guessing the p0300 is being caused by the p0155. Thats the pass side precat O2 if im understanding correctly. Is it as easy of a fix as a bad O2 sensor? I find it hard to believe that the car can run so horribly just from one bad O2.

p0140 and p0160 are the rears because they have not been tuned out or simmed.. and the p0418 and p0412 are the air codes because that system was deleted right? They shouldnt give me any driveability issues?

Cars a 01 Z28 with 85XXX miles. Plugs are only 3-4k old. None of the wires look burned or pinched... fuses look okay in both fuse blocks and in the dash. Im stumped

**7camaro7** · 07-05-2007, 07:19 PM

PO300 is a bitch. I had a coil pack/ plug problem. part of your problems could be an exhaust leak. mine was at the A.I.R. connection in front on the passenger side and it fouled all 4 of those plugs. I found it and tightened it up. Just make sure your ENTIRE exhaust system is leak free. Check to see if you have any cracked spark plugs. Replace your wires and coil packs and PO300 should go away. I dealt with that one for about 2 weeks. Get some plug in O2 sims too for the rear O2s

**kyemt** · 07-05-2007, 08:35 PM

i would also check and make sure your 02 sim wireing isint burnt into

**0rion** · 07-06-2007, 01:24 AM

what's the deal with your a.i.r. system? Is it still on the car? Are the pipes ok and not leaking at the header connections or the metal parts of the air pipe itself not cracked? Did you bend them around during the header swap? 155 is a common code with headers. When you put on headers you move the O2's further down stream and they don't heat up as quickly as the pcm would like so it bitches about it by throwing heater codes. The sensor 2 codes can be tossed out because they have zero input on fuel like the fronts do. That basically leaves your a.i.r. codes and the misfire code. 300 is a random misfire which just means it's not cylinder specific and you're missing on a couple of cylinders. I would pull a couple of plugs from each side of the motor and see what they look like. Any other symptoms before this started happening? Noticed any misfiring or anything along those lines? Check all of your plug wires and make sure none are even touching your primaries on the headers. It will dry those out and create cracks in the boots, seen it happen. I'm gonna go out on a limb and take a guess at this one. My guess is that you're getting extra air into the exhaust stream before the O2's and they're seeing a lean condition and adding extra fuel which fouled your plugs. Your deal sounds very familiar to 01raptor's problem. Pull a couple of plugs from each side of the motor and see what they look like. Another cause could be your extensions on your O2's. How confident are you of the connections? Solder, wire nut, or electical tape on those?

**mrr23** · 07-06-2007, 03:03 PM

if you want, you can bring it by my shop and i'll take a look at it.

i've had the P0155 not cause P0300. they will be two different issues.

**Corvettekid82** · 07-13-2007, 10:41 AM

AIR system has been removed, running race style headers.

Looks like one of the spark plug boots on the drivers side is pretty close to one of the primaries. Is there a specific brand of Spark plug wire that might give me some clearance there or maybe have an angled boot instead of a straight one?

I bought new O2s for the fronts.. the bosch 13111's so they're already the correct length without extending them. That eleminates the possibility of me screwing up the wiring (just one less thing to worry about).

In planning to get the AIR and rear O2s codes tuned out.. but I have to have the car running properly to even get it to a shop. Right now Im too scared to even take it around the block its running so rough. I gotta track down this P0300 first. Hopefully its as easy as a fried spark plug wire.

Im going to double check all the connections on everything, retighten the header bolts and install the new O2s and report back to you guys. Im sure the plugs have seen better days as well.. I'll pull a couple and take a look.

Thanks for the advice and help!

**Corvettekid82** · 07-13-2007, 02:05 PM

plugs had some black soot on them, but wiped off easily. Exhaust has a small leak in it where the headers join into the xpipe.. black soot from that spot gave the leak away as well. I isntalled the new O2s.. car is running strong again with no hesitation. No black smoke from the exhaust anymore either. Ran it for about 30 minutes and had the codes rescanned. Still throwing P0140, P0160, P0418 and P0412 but no sign of the P0300 or P0155. I dont know where the P0300 was coming from.. the spark plug wires were not touching the tubes, but one is pretty dang close. Im still going to get a new set of wires just in case. Not planning on driving the car anymore until I get the other codes tuned out and a good tune for the headers.

**mrr23** · 07-17-2007, 07:33 PM

well, i can help you out. would have to buy the $100.00 in credits, so i can open your file. i only have the 99-00 fodies fully open.

**dafizzman1** · 07-27-2007, 04:47 PM

where is a good place to get the O2 sims???

**Corvettekid82** · 07-28-2007, 07:25 AM

Originally Posted by mrr23

well, i can help you out. would have to buy the $100.00 in credits, so i can open your file. i only have the 99-00 fodies fully open.

Thats cool.. I'll take ya up on the offer. PM me when are you available and we'll meet up. Im just afraid I'll be on the juice too by the time you're done with me

**mrr23** · 07-28-2007, 04:15 PM

Originally Posted by Corvettekid82

Thats cool.. I'll take ya up on the offer. PM me when are you available and we'll meet up.

i'm available most evenings and weekends.

Originally Posted by Corvettekid82

Im just afraid I'll be on the juice too by the time you're done with me

you've been talking to someone haven't you????

**Eagle** · 07-31-2007, 10:47 AM

Originally Posted by Corvettekid82

plugs had some black soot on them, but wiped off easily.

You've got exhaust leak problems bud. Its running rich because the O2s are seeing fresh air from somewhere... make sure everything is sealed up properly, clean the O2s and see if it calms down...

Either that or let mrr solve your issues for you!

-Eagle