I took my C6 to my first HPDE event up at Limerock Park on Thursday the 14th.... Awesome time and can't wait to do it again. BUT... after the second session I noticed I had the CEL on. I checked Oil Temp, Pressure, Coolant, Tire Pressures, brakes, etc and all seemed to be operating fine. The car was running nicely so I kept going. I ran two more sessions with the CEL on and got progressively faster and more aggressive. I was running hard in 3rd and 4th gear (Z51 package with M6, CoW booster but basically stock car) for all these sessions. I was running with all the Nannys on as this was my first event and I wanted to be as safe as possible.

I got home and checked the Codes with my ELM and reader software. I got P0101 MAF Circuit Performance and P0201 Injector 1 Problem.. I cleared the codes and only the day after getting home did I notice that the car is idling rough. After coming to a stop (at a light, etc) it will idle at approx 600-700 then surge up to 1100 - 1200 and then fall back down and stumble at 500-600RPM.

Today, I changed my oil and filter, put my ceramic street pads back on and generally cleaned up the car (it was filthy and wheels covered with rubber 'pellets' from the track... what a hoot). I had the car out to run up the oil temp a bit and after it got warmed up, I punched it in 2nd gear close to WOT.. The CEL came back on...

Checked the codes again and I get P0201 (P0101 did not reappear) and two that I can't identify... C3101 and C3400.. These seem to be be undefined for LS2. hmmm?? Anyway, I cleaned out my stock air box, and filters. I didn't take out the MAF sensor off to clean as I ran out of steam today. I also checked all connections at Cylinder 1 plug, wire and coil.. All looked good.

Soooo.. should I just get on down to CoW or does anybody else have any suggestions?? It's interesting that running the car HARD at the track seems to have brought on these Codes and Idling issues. I drive aggressively on the street but obviously not 120MPH and WOT for 20 mins at a time. After clearing the codes, the CEL stayed off UNTIL I punched it in 2nd gear this morning... That's my story. Hoping somebody has some wisdom to impart..

 

C3101 & C3400 , i cant locate those codes anywhere. if someone can, please post the link with them.

honestly, my first thought is, they are error codes for your reader. they actually are valid C/C++ programming language error codes. like your reader is saying.. 'processing error , does not compute'.

 

I would clean up he MAF and pull the #1 plug for inspection. That may give you some clues.

BTW, did you run he rest of the day on the track without knowing which engine codes were present? Not smart IMHO. Too much at risk with your car.

 

Yes I ran the rest of the day... As I said I couldn't find anything wrong other than the CEL and the car was running well (at the track).. I know I probably should have quite for the day, but I looked forward to this for weeks and it was too much of a bummer to just quite.... (maybe) my bad.. on the General Forum other have suggested that running at the Track with all the Nannies on is NG... Taken, I'd like your 'take' on that.. I'm a drop dead novice... TC on or off?? Comp Mode for the track as a beginner?? THANK!

 

I would hate to waste a day at the track as well, but without knowing the codes and being able to determine if it's a show stopper or not is a big risk. What if number 1 injector wasn't putting enough fuel into the cylinder and it ran lean all day? Could have done some damage and you may have never known it until it was too late. An injector malfunction may not give and audible clues that something is wrong.

I'm no expert on the track by any means. I run with TC off but don't have the courage to turn off AH. I would rather be called a wuss than put my car in the wall cause I didn't react fast enough. Being a beginner, I would run in comp mode until you feel that the car's nannies are holding you back (a long time away most likely). Others may have a different opinion but I'm not driving for money or trophies... Yet.

Sean

 

I've been open tracking every month for the last year. I just started tracking the corvette the last 4 times and I still run with the traction control on. You will feel it and see a message on the DIC when it kicks on. Mine rarely comes on unless my tire pressure is too high so I just leave it engaged. I'm still concentrating on being smooth and carrying momentum rather than going all out.

 

1. Check the connection and wires at the fuel injector.
2. Check for voltage at the injector.
3. Swap one injector for another and see if the code changes.

 

That's a good idea. It should help you narrow down the problem.

 

whats involved in swapping the injectors?? Not sure as I haven't dug into that part of the engine yet... Hmmm. Do I feel up to this??

 

It's easy.

Remove the 8 injector connections.
Remove the 4 fuel rail bolts
Gently pull up on fuel rail
Remove the clip holding the injector to fuel rail
Swap 2 injectors - be prepared for fuel on your hands
Install is reverse of removal

You can probably have it done in 20-30 min.

 

I checked the Resistance at three injectors.. All measured 12-1 - 12.3 ohms.. I checked the voltage at the Injector Connector.. same as other injectors. Engine tone changes the same when I disconnect Injector 1 or 3... I have NOT swapped the injectors yet... I think the injector is dirty.. (my theory).. Is there a cleaning procedure?? I hope to take off the fuel rails and swap the injector tomorrow to trouble shoot further... Just wondering what to do with a fouled up injector if that is indeed the problem.

 

So, one item I didn't include in the original post.. My NPP in a Box stopped working during the Track day. Noticed the fact that I couldn't close the NPP on the way home. My NPP exhaust was stuck open. My hardwire switch and/or the remote would not close it. I figured that I either punctured the vacuum line, melted it, or it fell off somewhere. I checked all the Vacuum and Elec connections when I got home including the run of hose under the car and couldn't find any problems... I put this on the side while I was trying to get through the rough idling and the CEL/DTC codes.

Anybody guess what happened?? I disconnected the battery today to reset the ECU. I also removed the vacuum hose to the NPP and reconnected the sensor at the Intake that is used for the EZ-Tap connection at the intake without the "Y" connection...

All problems solved. The CEL is cleared. The Idle is normal, there is no hesitation at low throttle and I took her out for a nice ride including several WOT runs and no CEL returns... Looks like the "Vacuum leak" is the source of the problems. I still have to find the Vacuum hose issue but that I can handle.

Thanks to all the help and suggestions. Looks like the injector is fine and car is running great now. It was HOT here today and the temps got up there during my 40minute run... no issues with anything.

I just didn't make the vacuum connection for the Injector codes, idle issues, etc. (Thanks Phil).. My gear-head buddy who I was at the HPDE with and who is teaching me limited maintenance items with the car put it together as we were on the phone today... He asked if I had fixed the NPP yet.. then he suggested removing the NPP vacuum hose from the equation.. Others had suggested the Battery lift to clear the ECU for sure. Thanks again everybody!!...

I still want to get over the CoW for ARH headers and a tune, so I'll have him check the Code history and obviously while he does the Tune he should see anything that is not right.... Whew.. glad to have the vette back working correctly.. Now, just gotta fix that NPP Vacuum line.