i was wondering ... if you have codes stored on your computer.. codes in history, not in current... will this in ANY way effect your car...

 

I say no. If you have a code, let's use 17, O2 sensor code. If you fix the sensor/wiring, the code will always appear until you clear it out, but it won't affect the running of the vehicle once it's corrected.

 

i couldnt agree with you more... but the guy at canadian tire said it would.. he said you must clear codes or the problem will persist.. i disagreed with him, and insisted it wont... and he argued how im not a class A mechanic.. this guy is the boss in the garage part of canadian tire... and isnt code 15 the o2 sensor on a mazda.

something else i was curious about... does anyone know how long codes in history will stay stored on the computer... whether its obd2 or the style b4 that

 

Well for our cars once you disconnnect the battery for a few seconds (and hold the brakes to make sure all power is drained) the CEL codes will be cleared.

 

i knew of that trick... does that go for any mazda, and how long will they stay on there own unless you clear them... and it that what the codes were called prior to obd2 (cel that is).. and i need to get a second opinion on leaving codes in history

 

CEL= check engine light

The codes should stay on your car until you clear them by fixing the problems and/or resetting the ecu.

 

Well... here's proof.

Car spat out a code 30. Split air solenoid valve was cut. Made a new male -> female adapter and plugged it back in. Valve opens fine. I don't know if it still has the code or not, but I never cleared codes.

S4s dont even store codes. Once you turn off the car... that's it.