J S Machine

'99 C5 coupe MN6. No serious modifications other than a vararam and a catback. No catalytic converters either.

My car has been running funny for some time..I notice it at idle. Kind of sounds like it has a cam. I never really noticed it before the other day, but someone standing outside of my car said it sounded like I have a vaccuum leak. That person said they smelled gas.

Today I opened the hood and the sound is so bad it sounds like someone pressing an air blower nozzle hooked to an air hose. My wife came ouside, and she said she smelled gas too. The sound is more evident coming from the passenger side. I unscrewed the oil fill cap to remove the fuel rail cover, and the idle dipped even lower and became even more eratic. Almost like the car was struggling to run. replaced the oil cap and rpms went back up. I could not find a source of the air noise.

Also, the service ABS light (and traction control message) comes up intermitently. It has been happening alot more lately.

I pulled codes today and this is what I have.

10-PCM
P0174 H C Fuel Trim System Lean Bank 2
P0171 H C Fuel Trim System Lean Bank 1
P0420 H C TWC System Low Efficiency Bank 1
P0430 H C TWC System Low Efficiency Bank 2

28-TCS
C1255 H EBTCM Internal Malfunction / CEBCM Internal Malfunction

40 BCM
B2723 H PASS-Key Detection Circuit

AO LDCM
B2282 H Battery #1 Fault
B2284 H Battery #2 Fault

A1 RDCM
B2239 H Right Door Un-Lock Switch Fault
B2205 H Right Window Down Switch Fault
B2283 H Battery #1 Fault
B2285 H Battery #2 Fault

BO RFA
C2100 H C Left Front TPM Sensor Malfunction
C2105 H C Right Front TPM Sensor Malfunction
C2110 H C Right Rear TPM Sensor Malfunction
C2115 H C Left Rear TPM Sensor Malfunction
C2121 H C TPM System Programming Malfunction (No Sensors Programmed)
U1255 H Serial Data Line Malfunction

I do not have tire pressure monitors, so this is the cause of the RFA codes. I do not recognize the U1255 code.

Any ideas?

Thanks

Wicked99

John, A lot of those codes are history. So if you cleared them, half of them will not come back. The ones with the C after the H are current. Most of them probably showed up after your wreck. If you want to use my GM tech manuals you can. Or I can stop by your house and give you a hand figuring it out. The PCM codes are the only ones you need to be concerned with.



Eric

KOZ

Follow the hissing sound to your vacuum leak.

J S Machine

I'm thinking it may be a vaccuum leak too. I hope it isn't an intake gasket or something. Are there vaccuum lines under the intake manifold?? I looked briefly, and couldn't tell where it was coming from. It may be somewhere unseen.

J S Machine

Yes Eric, I know most of them are history and probably from the wreck. I cleared everything, so we will see what comes back. I have a feeling the ABS stuff may be another problem though, as often as I'm getting the light for it.

Wicked99

John, there is no vacuum lines under the intake. But you could have a bad intake gasket, easy to fix.

J S Machine

Got in this morning and had no SES light. ABS light and traction control came on right away, and stayed on all the way to work.

What is odd though is the lack of SES light. I have cleared the codes before and I don't remember the SES light ever going away. This is do mostly to the lack of catalytic converters..My car is a '99 and the O2 sensors cannot be turned off with a tech 2. I have always had a light because of those being missing.

rebelheart

If you dont see or find an obvious vac leak in the duct work leading to your MAF,try looking around under your battery at those vacuum lines,they may have been damaged in the accident.

J S Machine

This accident happened back in October. I hit a deer. No real significant damage. The car did leave the road, but no real damage.

That doesn't mean it could have causes something though. I'll check it out.

0EG@EnglandGreen

Check your PCV system on the passenger side of our intake manifold. The rubber coupler disintegrates on almost all C5s and will cause many of your idle and noise symptoms. Also check your Air Pump connections close to and at your exhaust manifolds.

The "C" codes are probably your ABS plug loose or a failing ABS module. Check http://absfixer.com for more details and a possible fix.

Stephen

rebelheart

Also a Vararam system does make a intake noise from the outside of the car,some may think that is a vacuum leak,but is perfectly normal.