Help! Few questions about my LT1 corvetter (1992)

[Darksaga]

It's a 6 speed, LT1.

I had a few questions I wanted to clear up.

Question #1:

I notice after driving down the highway for a while the CEL will come on then go off after several minutes. That's the only time it will come on and I can't figure out why.

Question #2:

I notice at idle the exhaust sound is off. If I can post a video I will but it just seems like a slight miss or infrequent exhaust note.
The idle RPM is fine though, doesn't fluctuate unde ror over 800 or so RPM.

Question #3
When I shift at around 2,500-3,500 rpm or above in 1st, and 2nd gears (The lower gears) I notice a quick popple/crackle sound from the exhaust, it's fairly loud to what I'm used to in other manual cars.

Question #4:

How many O2 sensors are on this car and which are the ones that usually need replaced? I bought a couple NTK upstream sensors since they were reasonable and made by NGK.

Question #5:

How do you reset codes?

 

[Hib Halverson]

It's a 6 speed, LT1.

I had a few questions I wanted to clear up.

Question #1:

I notice after driving down the highway for a while the CEL will come on then go off after several minutes. That's the only time it will come on and I can't figure out why.

There is a problem with your engine controls system. Without knowing what fault code is set, few of us will know why, either. Information on how to get the ECM to reveal fault codes is in this article here on the CAC. Post what codes are set and maybe we can be of more help.

Question #2:

I notice at idle the exhaust sound is off. If I can post a video I will but it just seems like a slight miss or infrequent exhaust note.
The idle RPM is fine though, doesn't fluctuate unde ror over 800 or so RPM.

Some engine controls faults which turn on the MIL may make the engine sound differently.

Question #3
When I shift at around 2,500-3,500 rpm or above in 1st, and 2nd gears (The lower gears) I notice a quick popple/crackle sound from the exhaust, it's fairly loud to what I'm used to in other manual cars.

No good answer for that.

Question #4:

How many O2 sensors are on this car and which are the ones that usually need replaced? I bought a couple NTK upstream sensors since they were reasonable and made by NGK.

Two O2Ses. One on each side just ahead of each cat.

Question #5:

How do you reset codes?

Disconnect the battery for ten minutes or use a scan tester to clear codes

 

[Darksaga]

Thank you very much for the info. I'll try to jump the codes today and see what comes up. I wasn't aware that was possible.

 

[Hib Halverson]

Thank you very much for the info.

You're welcome.
Glad to be of service.
Please, post any DTCs you read from the ECM.

 

[Darksaga]

You're welcome.
Glad to be of service.
Please, post any DTCs you read from the ECM.

Just jumped it doing the diagnostic center A to G.

Codes"

1 - C12 Then 1. --- flashed
4 - H65 Then 4. --- flashed
9. --- flashed

Then it was on "1.0" which I assume is nothing but the ending screen

 

[Hib Halverson]

DTC65 is the rich exhaust code for the right bank.

Do you have the Factory Service Manual?
Do you have a scan tester? if not, do you have a DMM?
Do you have a fuel pressure test gauge?

 

[Darksaga]

DTC65 is the rich exhaust code for the right bank.

Do you have the Factory Service Manual?
Do you have a scan tester? if not, do you have a DMM?
Do you have a fuel pressure test gauge?

No service manual
No scan tester but my uncle has a professional one he would probably use on it
Yes I have a FPG

 

[Hib Halverson]

Well, you probably need to buy a Service Manual. The diagnostic information in it will help you decide if your getting that code because of a fuel-related problem or an electrical problem.

You need the scanner or the DMM to see O2S output.

Good luck.

 

[Darksaga]

We just installed 2 new NTK O2 sensors and reset the computer. Cross my fingers it seems to be helping a lot.