Hey there, i recently installed LT's , catless xpipe and catback on my 09 C6 and after that install i had what sounds like missfiring and related ignition issues when reving the car around 5k rpm so i didn't push my luck there. I have yet to see a CEL show up, even if the car is behaving pretty bad , i went for a drive with it today and it stalled quiet a few times ( telling me to service traction control when it did ), even had issues with the accelerator pedal not doing anything for a couple seconds then coming back alive . Ended up stalling in front of my driveway ,not able to restart the car, starter motor spins but the engine won't fire up.

I checked if i had plugged the rear O2's correctly, as well as the front , they seem ok , only issue we had when fitting the parts was the car wouldn't start because we bolted a ground in the wrong place , we corrected that and it started imediately. I'm going to go over all the fuses , and wires to check if something is wrong or not , will scan the car tomorow for codes ( didn't have any yesterday) .

Did this happen to someone or does anyone have an idea on what it could be ? I thought maybe damaged battery ( from ou first engine start try )or bad grounding f*ing up the electronics ?

 

Spark plug wires in the wrong order?

San

 

what do you mean in the wrong order ? ( they're not crossing or anything )

 

Check for any vacuum leaks around intake tube and for Mass Air sensor connection even remove sensor and visually look inside for debris stuck to the wires inside check plug at throttle body. On a drive by wire system it relies on these inputs to know what is going on with the engine according to driver input if one goes out it will fail safe to limited power or no pedal response

 

what ground did you have to touch in order to install headers??

i'd replace all the spark plugs, maybe you broke one during the install.

 

after discussing with the people that did the install it seems that the wire that was missplaced is one of the wires that is on the passenger side of the engine , bolted to the block , the bolt is visible between the 1st and 2nd header runners starting from the firewall on that side. It seems it was bolted on the rear of the starter first and it could have made a short circuit if it was bolted by mistake on a + line

Spark plugs have been all changed , same problems.

 

why would they even touch that wire? it was not necessary. but anyway if there was a bad short such as that, i think you would have more problems than just a slight misfire

 

i don't know why it was done.

I do have more problems than a slight missfire , it evolved into stalling , accelerator issues and now the car won't start. , checked all the fuses , now i need to check with another battery and try and find some diagrams to see if all the wires that have been bolted back on the engine are in the right place.

thanks for you support by the way

 

True, could be you messed up the engine harness. Any other electrical probs?

I hope the shop is paying for all this.

 

i'll manage the thing with the shop no worries for that. Electrical probs , well appart from the car not starting now everything works fine, maybe except for the fact it doesn't give me errors at all, appart from the 'service traction control' that i got when the car stalled on the highway

 

Logically it must be from the install.

1 - So look for burnt wire
2 - What sensors, wire connectors were R&R during the install. Recheck these connectors for contact and proper location
3 - Loose battery cables

Maybe a concurrent BCM failure.

There was also another thread about a no start (everything worked, but no start) that ended up being a wire connector on the starter.

 

Holy HELL! They put the GROUND WIRE on a POSITIVE terminal! Check the DTCs and see if the codes will point to a specific module, sensor or circuit.

They could have damaged the PCM or BCM or a sensor. Hard to tell with out DTCs. Could also be something as simple as a vacuum leak.

That ground mis-wire could be a real Headache. Also make sure that they have it properly connected and properly tightened.

There have been a few similar problems like this on some C5 and there was no lasting electrical damage. The C6 is a little more complicated and sensitive to issues like this.

PLEASE keep us informed on the results and outcome.

Bill Curlee

 

ok so connectors have been checked again this morning , voltage on the battery as well , current assumption is that some sensors or ECU is damaged. Probably the sensor that had its ground put on a + terminal. Can someone give me a hint as to wich sensor it is if i get a picture of it ? I don't have a wiring diagram for this car yet so i can't tell. Or if someone has a scan of that particular place's wiring diagram page and PM it to me it would be very helpfull , I live in a remote place and having sensors or a manual shipped to me will take weeks at best so anything that helps me point out what is wrong will make for better sleep later

cheers and thanks again for your help

 

Hmmmmm! Your NOT going to be happy. Ground G-106 is not the ground for ONE circuit of sensor.

It is ground for the ECU, Transmission Control Module & MAF?Intake Air Sensor. Like I stated. Its best to get a Scanner and see it there are any specific DTCs that will point to one specific area or component.

Try this: Disconnect the battery and then reconnect the battery, it just might help but its not 100% the cure. (Remember... You will need to re-index your windows and set your memory stuff again after you reconnect the battery.)






BC

 

cool thanks for the info, hopefully i'll be able to scan the car tomorow and figure out what i need to order , will probably end up getting a new ECM and MAF .
Stupid question though , i have a M6 , does the car have a TCM ?

 

No It does not

 

make sure all of the coil packs are plugged on properly. When I did header install on my C5 I forgot to plug in the driver side coil packs and I had the same problems your having right now. check those

 

i double and triple checked the coils / plugs / plugwires / etc and we tried checking the ecm with efi live , we got no DTC's from it and we're leaning towards a damaged ECM because we got some errors like 'ecm not responding / not sending info' etc when we tried some other diagnosis features (SMS etc ) I'm looking into ordering a new ecm / MAF sensor. ( my battery died out as well so i guess the electronics in the car took a good hit )