not quite sure what's going on here, chipped p28 CEL with no code?

[teh_mugen18]

the title says it alll. I turn my car on, and the light comes on and turns off when the fuel pump is finished priming the car. I then turn the ignition key and start the engine, and proceed to drive as normal, with no check engine lights or codes or anything. But, later on maybe 5 or 6 miles later, as i continue on driving normally, the CEL will come on in the car with no side effects; no driveability issues whatsoever. Then, when i turn the car off,jump the harness and turn it back on to check the code, there is no code and no check engine light once again.

What's going on here? :thinking:

[Barefoot]

the title says it alll. I turn my car on, and the light comes on and turns off when the fuel pump is finished priming the car. I then turn the ignition key and start the engine, and proceed to drive as normal, with no check engine lights or codes or anything. But, later on maybe 5 or 6 miles later, as i continue on driving normally, the CEL will come on in the car with no side effects; no driveability issues whatsoever. Then, when i turn the car off,jump the harness and turn it back on to check the code, there is no code and no check engine light once again.

What's going on here? :thinking:simple dont turn the car off before u pull the code.

[teh_mugen18]

i wasn't aware that you could pull check engine codes with the engine being on?

[jcs]

yea just put the key in the on position if im not mistaken

[Barefoot]

i wasn't aware that you could pull check engine codes with the engine being on?yup

[TommyD1919]

yup times 2

[teh_mugen18]

well cool then