Im just wondering its not a problem dont even car for it but i can make a code condition and i wont eveb get a ck engine light. now before yall ask the light does work and comes on with key on and goes away when i start her. she is a 89 5 speed. do any of yall know why this is

 

Is the ECM **** turned all the way to the left?

 

From what I've heard the car has to be so bad (barely running) for our obd1 system to throw a code.

 

The difference between OBD-1 and 2 is the tolerance. OBD-1 systems throw codes if there's a problem that occurs more than ?twice? in a certain number of cycles. OBD-2s give codes if the problem is 1.5x greater or lower than the spec.

 

OBD2= more sensitive.

 

You can say that. But my point is, for OBD1s, if it's not there, no code, if it's there, you have a code.

 

They are not terribly sophisticated. The onboard computer in my 2003 E46 tells me more than the old Consult reader I had for my Maxima I did a lot of crazy stuff with my old VE and it never threw a CEL. In fact on all of them, the only time I ever saw them was on other peoples cars (and no the bulb wasn't burn't out )

Another problem is half of the old OBD-I systems would clear the code when it loses power, which can be really annoying. They also don't have the quickest sampling rates.

 

That is tru, the only time my check engine light ever came on is when i pushed in the egr valve thing, on purpose and the engine nearly shut off. Also if you forget to turn the ecu bak the right way, it will flash. Other than that, no other issue will make that light come on.

 

In all the time I have owned 3rd gens (about 15 years total) my cars have only thrown one code TOTAL. That was for a bad coolant temp sensor. The CEL light did not come on, either, it just had the code on the ECU.

In other words, it is pretty tough to get a code to appear on these cars. OB2 is a totally different story, they give you lots of info.

 

IIRC, It should always give a code. Code 55 which means ?everything? is good.