brit2001

I have been having this problem for months and just can't fix it. The car has headers, high flow cats, BBK intake,throttle body and manifold. 3:42 rear end, yank 3200 stall and dyno tuned by Charlie at RPM in california. The car will periodicly start to surge and sputter at 30-40 mph and 1000 rpm. Some times the check engine light will flash and go out and some times it will set. It has happened to me two days in arow now but will than not happen for weeks. When the check engine light flashed three or four times and didn't stay on I checked for codes when I got home and had: P1415 - air system bank 1, P0300 - random/multiple cyclinder misfire, P0175 and P0172 - fuel trim banks 1 and 2 too rich, and finally P0155 - 025 heater circuit bank 2 sensor 1 malfuction. Today it surged and the check engine light came on and stayed on and set codes P0175 and P0172 - Fuel trim bank 1 and 2 too rich. I have checked the grounds under the battery, drivers side engine block, and the ground by the drivers side headlight. Any one have any ideas I'm open to them. Thanks in advance, Laurence

Jonota

Has the AIR system been disabled or removed?

It sounds like an ignition problem to me, wires too close to headers, or one or more ignition coils failing. If you get a misfire (the 300 code and the flashing check engine), it will sometimes set a fuel trim code. Were all of these codes current (C) or some history (H) ?

Jon

brit2001

Jon, They are alway history. I have cool socks on the plug wires. Thanks Laurence

TS6

Have you actually checked the plugs?

0TheRadioFlyer97

I'm almost certain your front O2 sensors are crossed. My car expereinced the same symptoms....some call it "tractoring"

After about 2-10 minutes of driving, the car will seem to return to normal. What the computer's doing is reverting back to base fuel maps and ignoring the O2 sensors. You'll have a check engine light too.

brit2001

I had the headers on for a couple of months with no problems. the problem did not rear its ugly head until a couple of months ago. I'll double check the O2 sensor routing though.

brit2001

No I have not pulled the plugs. I'll have the problem two or three days in a row and than every thing will be ok for a couple of weeks. That is what is driving me up the wall. It is an interrmitten problem.

Stickman81

Just a guess on my part, but I say start with the wiring on the left side front O2 sensor.

Best of luck.

brit2001

I'll get under the car today and see what I can see.

bgreen83

Good luck,keep us posted.

brit2001

Got under the car and from what I can tell the O2's are ok. I didn't find any wires broken or touching the headers. I've been wondering if when the torque converter locks up and such a low rpm that it could be bogging down the motor almost like shifting from 1st to 6th.

dobewillie

hope you find the cause of your problem good luck

2vettes2go

maybe you ought to check the fuel pressure, or it may be a partially plugged fuel filter....

brit2001

I drove around today with the laptop and HP tuner scan on and the car acted up. So now I at least have some data to see what might be happening. When the car started to stutter and surge the LT bank 1 and 2 graphs what red so it looks like somethng is causing the fuel trim to go full rich. It set two codes ( fuel trim banks 1 and 2 too rich)but no check engine light. I sent the data to Charley at RPM with hops he could help.

0TheRadioFlyer97

Having a mid year C5, it's a distinct possibility that your O2 sensors may have just done dead...or be going dead. O2 sensors fail like batteries...slowly at first then completely. This would cause intermittant missing and occasional rich mixture.

how many miles do you have on your car?

vetterlatethannever

My buds TA was having problems like this. Never found out 100% for sure what was the culprit but seems that he was getting bad gas. Stopped going to one of the gas stations in his town and the problem has never returned. Could be that we had it scheduled for a retune, you know how that works- take it to the mechanic and the car works fine LOL!

Good luck!

brit2001

I have 74,000 miles on the car. When I was scaning the car with the HP software the O2 sensor grafts looked normal when the fuel trim went nuts. Maybe I need to change all 4 O2 sensors

brit2001

Charlie at RPM says from the looks of the data I sent him the O2 sensors are not responding fast enough. At least I have some idea what is the problem. Sent another scan and waiting to see what to try next. Charlie is the best.

love my car

Sounds like rich mixture to me...Keep us posted.and best of luck...........