Alright, instead of going to a reliable source or to an auto shop, I decided to come to Sup Forums...

Alright, instead of going to a reliable source or to an auto shop, I decided to come to Sup Forums. My 92' Buick's check engine light turns on, then turns off for a couple minutes, and repeats. Is there any way to diagnose the check engine light without a diagnostic port, could there just be a loose or rusty connection to the battery?

O2 sensor. You will need to get it fixed or replace it yourself

Thanks homie I'll check it out

Those have OBD ports. Get a phone app and a bluetooth scanner and you can get the code.

Go to Autozone or whatever parts store. They'll scan it at the store.

trade it in on a 93' Buick

Have you tried replacing the engine? When the check engine light comes on, it's time for a new engine.
Inb4: change the oil

>OBD1
Pretty sure OBD 2 came out 94-95 so I doubt he can read the codes with a code reader

'92 has a diagnostic port, it's just not an OBDII port. Go to an O'Reilly's with the nice code scanner and tell them you need OBDI for a GM car, they can do it.

I don't know if GM did this, but I know on Chryslers of the era you can also check without a scanner by turning the key on and off 5 times and counting the number of times the CEL blinks. For Chrysler, it's a 2 digit code, I'd look up GM code check procedure and codes and try that too.

OBDI still has a port. To my knowledge, the only one the parts stores can't scan at all is 80s Ford, which is some proprietary thing.

A '92 will be OBD1. There should be a single lead off the ECU that when you ground it, will trigger the check engine light to flash. The number represents a code you check. If it's flashing at two different rates, the code is double digits - fast for the first, slow for the second (or the other way around, I can't remember).

This is probably much closer to correct than my answer, I don't know GM.

Is the flashing check engine light a code for O2 or are you just guessing?

...

The only time a check engine light will flash is if the engine is having a type A misfire. Which means fuel is not being ignited and is being dumped into the exhaust system. But that's for an obd2 system. This is obd1 so it's out of my range.

Literally go to any auto parts store. Tell them you have a 92 Buick, which does have obd1 and they’ll just the port, you could the number of times the CEL flashes look up the trouble code and they’ll tell you what needs to be repaired/replaced. All for free.

It's just a guess without the code. It could be a number of things.

There is a specific flash code for the O2 sensor. I think it's 48, so four flashes at one speed and then eight flashes at the other speed (assuming that's the correct code - just look it up).

run through the general diagnostics.

>check for fouled plugs
>smell oil dipstick (for raw gas)
>check and clean throttle valve
>change oil and filter
>if auto, check tranny fluid
>check air filter

you get the gist. cel is code for something is wrong but not wrong enough to blow the engine. just run down all the crap that you can before going to a shop

I just had a quick look. OBD1 ran between '92 and '95. The "diagnostics port" is a two pin lead with one being ground, or a single lead that you just ground out. Look for your ECU and there should be an unplugged wire near it.

The long flashes represent the first digit while the short flashes represent the second. A code "36" would be three long flashes and six short flashes.

You have to observe the check engine light illuminated while the ignition is in the "on position", then turn it off, short the pins, then flip the ignition back on.

Find a code table online and figure out what your code means.

Yes this is correct. But since this is a GM vehicle, they had their own LFCs. So op will have to look up the codes specific to GM.