94 Suburban Service Engine Soon (Page 1/2)
Phirewire JAN 09, 12:38 AM
Just traded for a suburban but the service engine soon light keeps coming on and off, I don't really feel any change in engine or sound when its on. Any ideas?
Monkeyman JAN 09, 05:01 AM
Could be a million things, mostly emissions related. I've had a check engine light on on my Blazer for 18 months. I know what the diagnostic deal says it is, it's not hurting my gas mileage or drivability so I haven't messed with it. Most Autozones (maybe other car parts stores) should have the OBD II reader they'll use (for free) to tell you what the code is.
jaskispyder JAN 09, 08:14 AM
Yup, stop in to an auto parts store and have them read the code.
86soon3.4 JAN 09, 10:25 AM
94 uses OBD I.

Steve
jaskispyder JAN 09, 11:50 AM
easier...

"To pull that code you need to jump the diagnostic port. Take a wire or paper clip or something like that and use it to connect the 2 holes on the top right of the port. Turn the key to the "on" position (but don't start it) and the Check Engine light will flash to indicate numbers. It'll start out with code 12 which will show up as "flash" pause "flash flash". It'll do that a total of 3 times. After that it'll give you the code (or codes if there's more than one). It'll flash the number of times corresponding with the first digit, then a pause, then it'll flash the number of times corresponding with the second digit. Each code will be flashed a total of three times. All OBDI trouble codes are two digits. Once it's given you all the codes it'll flash code 12 three more times to let you know it's done. "

[This message has been edited by jaskispyder (edited 01-09-2013).]

1988holleyformula JAN 09, 01:52 PM
My money is on o2 sensor. I always had that code popping up randomly in both my 94 and later in my 97 Suburbans. Never really affected drivability, so I never took the time or money to replace it.
weaselbeak JAN 09, 02:56 PM
My 97 has seen this light off & on for 10 years. If it's full of oil and water, runs good and the mileage is there, I tend to not worry about it. Mines over 230,000K and doing fine. I found out years ago that I could spend a fortune chasing those little emissions codes around. I knew a Catholic nun music teacher who's brand new Taurus always popped up that service engine crap. After 5-6 times she said to heck with it. It never gave her any grief.

[This message has been edited by weaselbeak (edited 01-09-2013).]

jaskispyder JAN 09, 04:03 PM
The only time I would be worried is if it is the O2 sensor and you have a cat. converter. Otherwise, if it is an EVAP code..... ignore
Phirewire JAN 09, 08:37 PM
Alright, anyone have a list of info on the codes? So when i check similar to what the fiero list is?

Also Does cutting the cat off improve fuel efficiency?
jaskispyder JAN 09, 09:24 PM
I have a chiltons. What is the code?