Just bought a C5. It is in great condition, car has intake, full exhaust, catback and headers. The car accelerates great. Then it started to stumble under load and then cleared up. LATER a check light turned on, and with my scanner saw that it was code P0004 Fuel volume regulator control circuit high,.

I erase the code and car ran flawless. Then again it started to stumble again. What can be the problem?

1- spark plugs?
2- oxygen sensor?
3- MAF sensor?
4- other?


Please chime in

 

Year of car? Mileage?

 

sorry 2000. 15,000 miles six speed

 

I just looked in my service manual, that DTC does not exist. Perhaps you wrote the number down incorrectly.

 

With my OBD 2 scanner that was the code given. DTC 0004. When i looked it up.... Fuel volume regulator control circuit high

 

just talked to previous owner... car has no 02 sensor. check turn on again. 3 codes this time. P003 fuel volume regulator control circuit low. And P0140 and P0160 both regarding the 02 sensor malfunction.

I am going to replace the spark plugs and check maf sensor. Any other recommendations?

 

Why aren't you using the onboard system for pulling codes?

 

Your car is supposed to have 4 O2 sensors, two before and two after the cats and the previous owner says it has none???

 

You dont need no stinking scanner!!!!!! Try this. That way you will NOT see that generac stupid *** DTC deffinition.. By the way,, CORVETTE does not have a "Fuel volume regulator control circuit"

You have to have primary O2 sensors. You might not have secondary (after the CAT O2 sensors)

READ ING YOUR CODES!!!

READING YOUR Engine Diagnostic Trouble Codes (DTC)

This procedure should be carried out any time you experience a problem with your C5. Most inexpensive store bought aftermarket code readers will ONLY read power train DTC’s. Reading the DTC’s with the C5 built in code reader will allow you to read ALL the modules in the vehicle.

The Diagnostic Display Mode is entered with the following procedure:
1) Turn on the ignition but don't start the engine.
2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)
3) Press and hold the OPTIONS button
4) While holding OPTIONS, press FUEL button four times within a 10 -second period.

Initially, the on-board diagnostics go into an Automatic Mode which will cycle through each module and shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each module. ( i.e. PCM = 4 codes) If none are present in a given module, you will see No More Codes on the display.

There are two types of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current code indicates a malfunction is present in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes. More likely it's an indication of an intermittent malfunction.

Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.

Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except E/M. Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present; press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press RESET To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles. There are a few body module DTC’s that if set will prevent the module from operating properly. Once the DTC is cleared, the module will return to full function. This is not true for power train DTCs.

If you have never read and cleared your codes, there will probably be a lot of old history DTCs. It is recommended that you clear your codes and see if any come back during a driving cycle. Those are the ones that you need to concentrate on diagnosing.

Once you have the codes, the next question is: What to do with the information?
First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5.

NOTE and a WARNING. You can read the DTCs while the engine is running. I pull mine up all the time while driving.
WARNING. Don’t become distracted while reading DTCs while your driving and cause an accident!!!!! Use common sense and drive safe.

These are some very good C5 Diagnostic Trouble Code (DTC) explanation web sites!!! They also explain how to read the DTCs

Here are some very good sites that explain what DTC mean:

http://www.gearchatter.com/viewtopic11755.php

http://www.obd-codes.com/trouble_cod...d-ii-codes.php

Make sure to include the H or C suffix when you post your DTCs!!

 

Whoops,, forgot. If you seeing a misfire, it will cause the same issues. When the engine stumbles. look at the Check Engine Light (CEL) and see if it is flashing during the stumble. If it is, thats caused by a misfire Condition. Each time you shutdown the ignition, the P0300 misfire DTCs clear. After the stumble, just pull up the DTCs (without turning off the engine) and see what comes up.

BC

 

I'm not an automotive control systems expert, but perhaps he should start here:

 

no check engine during acceleration, i just ordered a fresh set of plugs, car had been sittin for a while and i just bought it and i believe a few plugs are fouled , thanx for the input, i keep you post it

 

probably only the 2 O2 sensor before the cats are still in the car, car has no cats, none, also previous owner is not very mechanically inclined and can't tell the difference from a spark plugs to a oil filter,

 

Need to follow Bill's advice and report codes.

If you've got fouled plugs, you've got problems.

Possible damaged plug wire from headers.

With no cats or rear sensors, those need to be tuned out or you will have check engine light.

Previous owner is probably playing dumb.

 

Problem comes and goes! I ordered the plugs but still have not installed them. Car starts and runs fine, then check engine turns on and when i checked the DTC codes says

-P0140-O2 sensor ckt no activity (bank 1 sensor 2)
-P0157-O2 sensor circuit low volts (bank 2 sensor 2)
-P0410- secondary air infection system malfunction

So can it be the Oxygen Sensor? which one? Are all 4 the same? Could it be a vacuum leak?

 

Congratulations on finding an '00 with 15k! Now the fun starts. First thing I'd do is purchase a service manual either in hardcopy or cd form so I could get up to speed on the various c5 systems. I'd also try to find out if any of the original parts that were taken off the car are still around. But that's just me...

 

Check the physical connections/location of the front sensors

 

Replace the plugs. A few plugs were fouled cause car didn't get move a lot just idle. Car runs much much better. I got a profesional scanner, and saw that I have 1 front and 1 rear 02 sensor not working. Just bought 2 front 02 sensors and a diablo to tuned out the rear ones.

 

The O2 sensor wires aren't flip flopped are they ?

 

Have n't really check the 02 cables. Hope they are ok. Just ordered the sensors. Worst case scenario, order the cables also. Should have check! Learning mistakes the hard way