Hi, I’m new here and I just got myself a nice ’88 Trans Am GTA. This is my first F body. I got it in a direct trade for a ’65 Oldsmobile. My car has the L98 350, T700-R4, no t-tops. This was my ideal spec really. So I am happy.



This is she ^^^

I have a question to get started with...

My car has the catalysts removed and dual exhausts with LOUD glasspack type mufflers fitted. Here in the UK we don’t have any emissions on cars pre-1992 so this is legal. It also has a cone type “high flow” air filter and a HEI distributor. I assumed they all had HEI but the guy I got the car from says no, this is a conversion.

My problem is that the “Serv Engine Soon” light comes on. The guy told me that “yeah, it does that, it’s because the cats have been taken off it gets a funny lambda reading occasionally”

OK, I can believe this.

Just about.

So how do I check? Are these cars OBD II so I should be able to get a regular off the shelf code reader and use that?

And is there any way to get around this? I would rather not have the light come on unless there is something I need to look at or how do I know if its “just” a wayward lambda reading or something serious I need to attend to? Heck, I might as well just take the bulb out otherwise...

So does anyone else run one of these without catalysts and get or not get this error and what can I do about it?

Thanks!

 

Take the bulb out. With the cat's gone, the computer will recognize that and set the SES light. Keep in mind that OBD systems run diagnostics on the pollution equipment. If it's been tampered with, well...

Good luck

OBDII came along in 96. Anything prior is a I.

 

its gotta be something else, because the SES light would only be affected by missing catalytic if there was an o2 sensor behind the cat location, these cars dont have an o2 sensor there, my car is missing the cat too, but the SES light isn't on, is the car running weird at all, surging, etc.?

 

Before you go and disable your diagnostic system, check out what code it is throwing. You need only a paper clip to do this. Turn off ignition. Jump the A & B terminals on the ALDL. Turn ignition on, but don't start the car. Light should flash once, long pause, then 2 quick flashes. This is a code 12. It should repeat this 3 times and then flash any stored codes. Any code will be repeated 3 times before the next code is flashed. Get the codes, then do a search (google or on this site) and find out what it means.

 

http://autorepair.about.com/library/images/bl428lib.htm

ALDL connector

 

Don't pull the bulb out! Not only could the reason it is on now not be a cat/emissions reading, it could be about another problem, but that would mean you would lose the ability to find out about any other problems that come up.

To find out what the light is for, all you need is a paper clip (or stop at Autozone & they'll read it for you):
ECM Trouble Codes

 

You mentioned an HEI dist. Is it a computer controlled dist or does it have a vacuum advance? I can't imagine it would run very well without the computer controlled dist, but I'm no expert there. As I understand it, ALL 3rd gens had an HEI dist, but they were computer controlled and changed timing advance/retard via the computer. But we usually don't refer to them as an HEI, even though they are. Usually, when someone mentions HEI they are referring to a vac adv dist that is not computer controlled.

Anyway - not having the correct dist would definitely throw a code.

 

Thanks for the replies so far.

I have no idea on the computer control or otherwise of the distributor, I guess if it is then it will have some extra plugs on it and no vacuum advance can. I'll check that when its light out tomorrow.

The SES light only comes on occasionally, not all the time, but yeah, now you come to mention it she does surge on idle when the light is on. She drives smooth but idles lopey, like she has a bigger cam in.

 

you should check your egr valve, because this was how F-150(I know its a Ford) was acting when the egr started to go out, the check engine light would only go off once in a while, and it would sometimes surge at stoplights, and once it got to the point where it stalled on me as I was coming to a stop

 

Pull the code. Hard to really chase a problem, until you know were to start.

 

I have an 86 and a 92 with cats hollowed out. Will this cause the check engine/service engine soon light to come on?

 

Ha! I stalled it in a parking lot earlier.

I'll get a code and check that, hopefully get chance to look at it properly Sunday.

 

update? i have a similar issue. im gonna get the code tomorrow