ECU code help

[co9738]

So here is my first post I never needed to post before I have had great luck searching but oh well. Anyways I have a 1993 q45 I always run 91 octane but this one time I tried to get away with 87 and right when I was leaving the gas station my check engine light came on check the code and I got the 55 system good light went out then back on. I ran all most of the 87 out and filled with 91 and still code 55 with the light on. So what should I do? Thought bout cleaning the MAF since i have gotten a little shake from time to time. Thanks for all the help.

[goody90q45]

Something sounds fishy here.......When you check the CEL codes by turning the screw on the back of the ECU does the CEL stay off for the first few seconds after turning the engine on and then come right back?

When you turn the screw to read the codes it should only be done one time to read the codes and a second time to clear the codes.

If you have a CEL, you should have stored codes. It sounds like you may be turning the screw twice before reading the codes. Instructions in the FSM are a bit hazy. I did the same thing the first time I pulled codes.

[Rex]

Are you following these steps?How To Pull ECU Codes and What They Mean

[co9738]

Yes those are the same ones I will retry today. How do I know when there are no more codes? Mine kept showing 5 5. So I thought it was done.

[elwesso]

yeah once you see 55 you're done...

It displays them in numerical order I believe... My guess is you have some iffy o2 sensors.. if the car didnt seem to change the way it was running you either had an o2 senosr problem or an EGR problem (if you were cruising).

Any history on the o2 sensors?

[co9738]

Ok I just needed to slow down I guess I was clearing my code before I read it or maybe I just can't count. Anyways I now have code 45 Injector Leak so should I check injector ohm or is it more on the lines of leaking o-ring? Thanks everybody.

[elwesso]

nope that proves your o2 sensors need replaced. If your car idles smooth then 95% chance all your injectors are fine!!

[co9738]

Ok when I get a chance I will replace the 02 thanks for the fast reply.