Help! Headers w/ tune

**Azchan63** · 01-03-2015, 02:32 PM

So I just got my PCM from frost which did a mail-order tune for me and I tried starting the car up but all that happens is that it cranks and then a couple of loud pops(backfire?) and dies. I tried a couple more times and it even started up for a little and then stalled out. The exhaust sound had a lot of crackling and almost sounded like I was cammed which I am not. All I have on right now is the headers so could that be the problem? I'm gonna try to connect the ORY to the rest of the exhaust tonight and try again tomorrow morning. Also the car is throwing three codes which ar: P0122 P0342 P0118. I've looked them up online but have no clue what they mean haha. Any input is greatly appreciated!

Thanks,

Aaron

***SMWS6TA*** · 01-03-2015, 04:52 PM

first one is your tps (throttle position sensor), next is cam sensor & lastly is engine coolant sensor.

step 1 check all connections. might have missed one or worse broke one.
tps is located on throttle body, cam is behind the intake & coolant is on drv side between the ps pump and header flange.

If all are connected then it's posible the sensors are bad. I'm betting the coolant sensor got bang up on header install.

The other 2 kinda hard unless you were doing something else.

You might also try a tps relearn. Disconnect the tps sensor, turn key on for 10 seconds, turn key off, reconnect tps sensor, turn key on.

***SMWS6TA*** · 01-03-2015, 05:12 PM

one more thing....running on open headers can suck clean air back into the headers and can effect the readings of the o2's.

**pajeff02** · 01-04-2015, 04:58 AM

Sounds like a ground wire is disconnected or broken.

**Azchan63** · 01-04-2015, 08:55 AM

I just recheck all the wires and all of them are connected. Before the header install everything was fine. How can the car throw these codes all of a sudden?

**Azchan63** · 01-04-2015, 09:44 AM

I also accidently dropped a nail in the EGR hole but I used a magnet to pull it out from the throttle body...could the magnet mess up the sensors?

**pajeff02** · 01-04-2015, 10:09 AM

You have three essentially unrelated sensors all throwing codes. What they possibly have in common is their ground point... and also their power source. You can also check your "ENG SENS" fuse to see if that is blown. Absent a ground or power issue, it is simply unlikely that all three sensors have failed. I will note that on initial startup (or anytime after the battery has been disconnected) our engines will stumble, possibly stall and may run like crap for several seconds while things get sorted out.

**Azchan63** · 01-04-2015, 10:50 AM

How do I check and how would I know the fuse is blown? And also I don't think its the connection problem bc I just changed the coolant sensor a couple of weeks ago.

**pajeff02** · 01-04-2015, 04:35 PM

Pop the cover off the fuse box located under the hood - front driver side of engine compartment. The fuses and relays are all labeled for easy identification. A blown fuse will be visibly broken (the wire bridge running through the center of the fuse) and have a burned look to it. You may have to remove the fuse to inspect it.

**Azchan63** · 01-04-2015, 07:53 PM

Ok I got the car up and running again, I cleared the code and it hasn't come up again. But the problem now is that the car sounds like its cammed...lots of ticking and the car shakes when it's idled. I think it may be exhaust leak....what do yall think?

**35th-ANV-SS** · 01-04-2015, 08:25 PM

As reference, the codes could likely pop back up if the underlying issue wasn't resolved. It takes X number of occurrences to happen before the PCM registers and triggers the SES light.

Have you checked for vacuum leaks? Ticking noise could very well be exhaust related....or a plug wire not on all the way.

**pajeff02** · 01-05-2015, 02:11 AM

Sounds a bit like a misfire and exhaust leak. That would cause the engine to shake. Double check your plug wires -- you should hear/feel one "click" as you push the boot onto the plug and two "clicks" as you push the boot onto the coil.

With the engine idling, start up top and see if you can locate the "tick" and then work your way under the car. An exhaust leak will generally leave a soot trail that can be seen. Check all your connections and if you find a leak between the engine and the front O2 senders you may be drawing outside air into the exhaust that will in turn create a false air-fuel reading.

**kingls1** · 01-05-2015, 06:19 AM

What gaskets did you use? Hopefully Factory GM as aftermarket gaskets will fail also new factory bolts. When torquing the headers Torque to 11 ft lbs starting in the center and work your way out evenly. Then go back over at 18 ft lbs. Don’t forget anti seize. Once that is done you should run a heat cycle and start to let it cool a bit until you can get in there with out burning yourself but still hot and retorque one extra pound to 19 ft lbs and that will help insure or help the bolts from backing out. I think Frost includes in instructions the car may be hard to start and stumble a bit until things relearn, and aprox. 100 miles until all fuel/air trims work out.

**Azchan63** · 01-05-2015, 07:25 AM

Annnndddd the car isn't idling again. So last night I took it out for a drive when it was running and one of the clamps fell off so I had to drive it with the clamp scrapping the ground, put it together last night and made sure it's tight this time lol, this morning I tried starting her up but no luck idling. When I start her up the rev jumps to like 2.5k and then just slowly dies down until it stalls out. Any idea what could be causing the problem? I unplug the battery thinking the reset might help but it didn't do much. The car sounds like it's an lawnmower lol and yes I used the gm gasket but I used the old bolts with anti seize.

**TransAmTerry** · 01-05-2015, 08:52 AM

Some other things to check would be the wires on the starter, working around the headers like that so close to the starter some times knocks things loose. Besides the main battery wire the starter there should be another smaller wire or maybe 2 and check for burned spots on wires close to the headers. Also, make real sure things are buttoned up real good on the intake area especially around the MAF. That happened to me once and the car ran like crap ( as you described ). After i re-installed my PCM from Frost, I had the usual and expected rough run for a short time but it straightened right out very soon. If you check everything and it's all good, I'd contact Frost and see what he says.

**TransAmTerry** · 01-05-2015, 09:48 AM

......and one other thing I just thought of. You could try disconnecting the PCM, inspecting the pins for any that might've gotten boogered in the way in and make sure the 2 connectors are seated properly. Just a thought and make sure you do the proper battery disconnect routine ! ...just sayin'.

**Azchan63** · 01-06-2015, 10:25 AM

Figured out what was wrong...it just so happened that when I went on that test drive that night, the rubber freeze plug that I put on the EGR hole on the I take popped off, car is in the exhaust shop getting welded up now. Thanks everyone for your help!

**TransAmTerry** · 01-06-2015, 10:59 AM

Originally Posted by Azchan63

Figured out what was wrong...it just so happened that when I went on that test drive that night, the rubber freeze plug that I put on the EGR hole on the I take popped off, car is in the exhaust shop getting welded up now. Thanks everyone for your help!

Wow,, the one thing no one touched on. I did suspect something on the intake side though. I'll have to stick that one in the ole memory bank !! glad you got it figured out.