OBD1 Check Engine Light

[Chase]

Hi, I have a 1994 saturn sl2(obd1) I keep getting check engine light when i reach about 50 mph. BUT after i turn the car off then back on again, the light is gone until i reach about 50 again. I did the paperclip jump thing and only got code 12. I am getting noticeably bad gas mileage, and am on a very tight budget. I am just so confused by the light. Any help would be appreciated! Thanks!

Topic

[college man]

according to the chart. code 12 is diagnostic check only.

Saturn

[Chase]

Yes, which means nothing is wrong with the vehicle. What I don’t understand is why i’m getting the code then..

[college man]

Did you read the code right?

[Chase]

Okay, I finally got a code from it. 32 (EGR system fault). Now, is that a major need to fix now problem, or could i hold off for now? Would that be the reason for bad gas mileage? Would that cause me to lose performance?

[Kevin Criswell]

[quote=”chase2604″ post=76563]Okay, I finally got a code from it. 32 (EGR system fault). Now, is that a major need to fix now problem, or could i hold off for now? Would that be the reason for bad gas mileage? Would that cause me to lose performance?[/quote]

Depends, an EGR stuck slight open can cause running issues, an egr not operationg at all can cause permenant engine damage in the long run.

One thing you have to remember the OBD I system is VERY different from OBD II. Many aspects of operation are not monitored by the computer, many OBD I systems can not even detect a misfire, so you need to do what is called no code diagnostics. Start simple check your plugs/wires/cap-rotor (if it has them) check your filters.

[Bill]

Those cars are known for the EGR vacuum solenoid failing. I have changed a few of them. You can test it with a couple of jumper wires from the battery Pos. and Neg. Unplug the solenoid and quickly touch the terminals on the solenoid. It should click when you touch the jumpers to it.

I wouldn’t panic to replace it but I wouldn’t run without EGR operation for ever either.

If you have emission testing in your location it might not pass.

[EricTheCarGuy]

An EGR problem can effect fuel economy and emissions. It can sometimes cause a miss under load. If it’s as simple as changing a solenoid however, it might be worth looking into.

Keep us posted.

[Author]

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