I just bought a 1988 GT and my check engine light seems to come on whenever I drive on the freeway. It never comes on when I drive in town only on the freeway. And when I turn the car off and back on the light doesn't come on... Unless I get on the freeway of course. I have checked for trouble codes and I got a code 32 and a code 35. What should I do to fix this problem? Any help is appreciated.

Welcome to the forum!

Did you check over the codes on the main menu?

Code 32 :EGR Vacuum Control
Code 32 is by far the most commonly encountered trouble code. The most common cause for this trouble code is a leak in the EGR vacuum lines. This code is often disregarded since a malfunctioning EGR system seldomly has any effect on the car's driveability, and only on the engine's emissions. It's also tremendously difficult to diagnose the problem. If your car passes emission tests and is otherwise running ok, it's often not worth the trouble trying to find the problem.

Code 35 : Idle Speed Error
The ECM will set code 35 when the engine speed is 75 RPM above or below the correct idle with closed throttle. This condition must be met for at least 45 seconds before the code is set. If idle speed is too high, check for vacuum leaks. If idle speed varies up and down, your engine might be running too lean (high air/fuel ratio). Check for low fuel pressure or water in fuel. If idle speed is too low, your engine might be running too rich (low air/fuel ration). Check for high fuel pressure or leaking/sticking injectors. Also, check all connections to the IAC and replace the IAC if necessary.

[This message has been edited by no2pencil (edited 05-07-2014).]

Yup I was going to say probably EGR codes... Usually because the EGR solenoid (UFO shaped thing on exhaust) get filled with carbon and stops moving. It's just emissions mostly... You can take it off and clean it, obviously check for cracks in your vacuum lines running to it and the EVP solenoid (what controls the EGR near the passenger side of the intake ) and check the wiring to that too. Otherwise get a block off plate, and a custom chip from darth fiero removing the egr code... Have fun! Mine was on for years, till I did my engine swap.

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1987 Fiero GTX 3800 Turbo... My Build, ST3 Cam, Lowered, Wheels, and pics enjoy!https://www.fiero.nl/forum/Forum1/HTML/089483.html

Yes I looked over the codes. I read code 32 and am not too worried about that as my car passes smog and runs perfectly fine. But with 35, my car seems to idle just fine but then again I'm not entirely sure. It idles around 14-1500 when warming up then drops to around 1000 or so when warmed up.

The idle sounds good. Your problem is probably a slight vacuum leak at the EGR valve or solenoid. Check the little rubber elbows for a tight fit...it does not take much to trigger a code 32.

I found this (again) & thought of your code 32 :

https://www.fiero.nl/forum/Forum2/HTML/122507.html

My 87 V6 automatic w/air idles between 7 and 800. Yours is a bit high.

Check your gas cap. The rubber seal may be old and cracked thus preventing a tight seal.