hi lookin for advice
I have had my 98 base c5 for 6 mos. now
here is what I have done
ran a can of 44k the fuel system
added a zo6 air cleaner lid with paper filter. I drilled two more 1 inch holes on top (I know should not have done that)
oil and filter change
always run chevron supreme
the car has ran very strong


now
full tune up
factory platinum plugs (did not check gap)
pcv valve
new pcv pipe old one was cracked
wires
fuel filter
added a k&n air filter (I think this might be the problem)

car runes good pulls strong
NO CODES AT ALL
but when the out side temp rises above 90 and the ac is on ...the Ls1 starts to ping a little bit as I do into 3 rd 4th and 5 th at the bigning of each gear. I have 3 different gas stations once again no codes. pls help

 

forgot to say k&n is stock replacement
in live in north part of ca.

 

Your engine really isnt suppose to Knock (ping) It has two knock sensors that suppose to put you into the LOW OCTANE table when the sensors sense KNOCK.

Im wondering if your engine was ever tuned and the sensors and Check Engine Light are tuned out.

How many miles on the engine??

If it were me,, I would find some one that can use EFI LIVE or HP Tuners and data log the PCM and see what is really going on.

Where do you live??

BC

 

hi bill I live in Rohnert park ca.94928 matt at gp tunning is about 1 hour away from me he can do a street tune for 400 dollars also I have rpm tunning local that uses hp tunning that one is about 800 dollars;;;; I have had other codes dot reffering to the motor so I know that works

 

sorry I do see the check eng light when I turn on the ingnation
also possible but not likely on a tune before I got it he was a older pc tech guy

 

sorry bill 89000 on the car

 

Are you using the built in DTC reader to read the DTCs????????????

READING YOUR Engine Diagnostic Codes



The Diagnostic Display Mode is entered with the following procedure:

1) Turn on the ignition but don't start the engine.
NOTE! You can read the DTCs with the engine running and or driving down the road but it can distract you. BE careful! Some DTCs clear themselves when you turn the ignition OFF!
I always read my DTCs prior to turning OFF the ignition switch. If you have any messages on the DIC,, PRESS RESET until they are gone!

2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect.)
3) Press and hold OPTIONS
4) While holding OPTIONS, press FUEL four times within a 10-second period.


Initially, on-board diagnostics go into an Automatic Mode which 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. ( 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 kinds of diagnostic codes, Current and History designated with a letter suffix, "C" or "H". A current C code indicates a malfunction is present and active 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 English/Metric (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 and hold the RESET button 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.
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. You can GOOGLE the DTC and also find information on it.




Here is very good site that explains the DTCs:


http://www.corvette-web-central.com/C5DTCcode.html


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



Make sure to include the H or C suffix!!

 

yes I have gone in to the dic it goes thru all the different blocks and nothing comes up ....is this what you guys mean

 

I use an ACTRON Scanner for my Jeeps and C6. I also use it on the C5 for a quick look at all the sensors to read LIVE DATA.

It allows me to see and monitor O2 sensor output in real time. Very important.

Bill

 

thank you for your help so far members