Just picked up my 96 LT1 from shop at dealership. The service man and the mechanic that did the work were already gone. The service engine soon light was on and I had them check this out. This was not the only work I had done. My invoice says "RUN SCAN, FOUND CONVERTOR CODE, PART IS DISCONTINUED THROUGH GENERAL MOTORS ". It doesn't say what the part is. I will be calling them on Tuesday. Has anyone else run into this or know what part they are talking about?
THANKS FOR ANY INPUT

 

Has the dealership , service writer, or GM mechanic that looked at your Vette give you a "P" series powertrain code to work with for the rest of us on C4 to know ?

There was a bad run on stator support shafts with the GM 4l60E transmissions.
That was some time ago.
From my memory now tonight 1996 C4 Corvette was not an issue.
There are current & history GM service bulletins(thousands of them) a consumer & avid Vette owner can check out online.
Use Google to look up "GM SERVICE BULLETINS"

Get the P series powertrain code they found with the Tech 2 scanner.

If they won't give you that code, then take your Vette & drive away.

Find a private small shop that will be more friendly & honest.

Brian

 

As mentioned without knowing the specific powertrain code any reply is speculation. What symptoms prompted the visit to the dealer?
Some transmission problems are monitored by the PCM on the 96, but I do not believe torque converter function is one of them. My guess would be a catalytic converter failing as monitored by the downstream O2 sensors.

 

The car was taken in for PM. The light has been on since I purchased the car in April. The car is running fine. I have not put but about 50 miles on the car since purchase. I am working on getting everything fixed, mostly small stuff. Previous owner did not really care for car as he should have.
This is off subject. I had a new oil pump installed just for my piece of mind. My oil pressure went from 40 cold to 60 cold. Idling after warm went from about 18 to 30. The car has 107000 miles.

 

Catalytic converters can die without any noticeable symptoms, but the car may fail emission testing if that is required where you live. If they become plugged however you will likely notice a lack of power.
Good luck with the car and welcome to the forum.

 

If this turns out to be the catalytic converter what would you recommend? Would GM discontinue a catalytic converter?
Thank You for the welcome. I'm sure I will be asking a lot as time goes on. This is my first vette.

 

If you need cats, and you want to replace them I recommend Random Technologies they make a quality aftermarket high flow cat specifically for the LT1 Corvettes.

 

i spoke with the service man today. He said it was the right bank of the converter. He said the mech could not remember the code number. He said not to replace one bank but replace both.
Could someone who knows about this make this clearer to me. I know nothing about converters. I am not real happy with the service at this dealership and will probably find another place when i need service.

 

When a Catalytic Converter fails on a OB2 equipped vehicle,
The Pre & Post O2 sensors in front inlet of the CAT & to the rear outlet,
The pair of 02 sensors start or do read identical voltage swings & at a same cycling rate.
This is not a normal condition.

In a properly operating CAT, the forward Pre 02 sensor will have much faster toggling rates or O2 counts ( 100 to 900 Milli Volts).
The Post O2 sensor after the CAT will read much slower( 100 to 900 mv also).
In a vehicle with a plugged CAT, both pre & post 02 sensors will about read the same.

A good mechanic let alone a decent ASE Certeified & GM Master Mechanic should know this.

Besides a Tech 2 scanner spitting out a DTC code for a bad or catalytic converter inefficient code he should verify the problem by watching All 4 O2 sensors on your 1996 Corvette on a Tech 2 data screen.
If honest also, he will show you the Tech 2 data table with O2 sensors working correctly or not.

When I was in the GM garages yet,
I would always explain to the customer to the best of my abilities in technical & layman terms.
Sometimes those Damn service writers would not let me.
Did not like my honesty I suppose or made that service writer look lacking.

Brian

 

An ex -GM Mechanic like myself & still current ASE Master Mechanic & ASE Advanced Driveability specialist would do an exhaust back pressure test to confirm indeed there is a bad Catalytic converter if unsure.

The Ex back pressure gauge is part of the GM essential Kent Moore tools kits required by all GM dealerships to have in their tool rooms.

I have my own Snap on Exhaust back pressure gauge kit.

It screws in to an 02 sensor port.

Heads up info for you.

BR

 

They know the Code.

The Powertrain code.

Its required for every " GM Technician" to hand write the "P" series code on a work order ticket.
Its a carbon copy ticket too.

Service writer stores one copy away.
Carbon copy goes on file in another locker.

GM head Honcho's can shut down a GM dealership if they don't play by these rules in place since 1969.

They have to keep every vehicle record on file for 10 years too.
Every vehicle that comes through the service bay door.

Your 1996 Corvette included.

Brian

 

Thanks Brian. Great information.

 

After talking to another person at the dealership and raising a little hell (not much) I got the info. The code is P0430, the part # is 25153070 and is discontinued by GM.

 

I've just read your posts and I have the same problem with my 96 vette. It has actually had the bank 2 sensor 2 code since almost new (under 1000 miles). Dealership replaced 4 spark plugs on the right side and 1 sensor. It has been and on going problem since 1996. Now with 60K on it it has the PO430 code. Right cat converter. I am wondering what you did for your car. Did your new cats have heat shielding? What brand did you use? Did the pass side have 2 O2 holes? Thanks for for any help and information.

 

i haven't done anything with the cats yet. I am working on other projects right now on the car. It seems to be running fine. I don't drive it much right now. When I get finished with the interior I will address the cats.

 

I just ordered some cats from ebay and I'll change them this week and see what happens. I feel since it was out of tune off and on for so long it may have killed the cat and if 1 is dead and I'm under there why not do both. Thanks for your prompt response and good wrenching on your project.

 

What cats did you buy? Let me know how it works out for you. Are you changing mufflers or running stock? Good luck with your project.

 

I ordered 2 cats from macautopartsdiscount in NY. I called and was told the passenger cat had 2 bungs for the O2 sensors. I had called the Magnaflow company and was told their 96 pass cat only had 1 opening for an O2. I felt the pair I ordered would be more user friendly. The ad said they were made in Canada by a company called Ultra Fit Brand. I was unable to find any info on the company but I thought at $400+shipping for the pair what the hey. I clicked on part of the ad and found they had a $20 off halloween coupon for buying over $300 and that helps pay part of the shipping. I have about 40K miles on the car and I think I will just keep the rest of the stock system for now. It may take me a while to change them but I'll let you know how it turns out. J96.