QuestionI have a 98 eclipse gs, my check engine light is on, i have a OBD reader for my engine. th e code was a emissions below threshold, and also i have a code for small evap leak, i have now clue what is rong i put a hole new aftermarket exhaust on my car from the headers all the back to the muffler, so if u had any idea what those codes could be pointing to that would be helpful. I also have a problem starting my car sometimes it will just keep turning over and over, then it might start chug a little bit and then shut off, then i will start again and run fine. It is so confusing and realy frustrating with these problems and i drive a 100 miles a day for work and i need to depend on this car.
AnswerThe actual code #s would be helpful. The small evap leak is indicating that the system cannot build up enough pressure fast enough during the evaporative system test. This can be caused by a leaking gas cap (check the seal on the cap, or even replace with the correct cap as it's cheap), a defective leak check pump, bad vacuum or evap supply lines, vent solenoid or purge solenoid. A good visual inspection of the evap system hoses and connections would be first, followed by using an evap system tester to inject an extremely low pressure mix of smoke to pinpoint the leak. This test typically takes me 10-15 minutes, and most shops charge around an hour for the diagnosis. A large leak usually indicates either a ruptured line or a loose/missing gas cap.
Emissions below threshold...not sure of your obd readers interpretaion, I need the code. Possibly O2 amplitude or rise/fall time not passing the threshold, but need the code.
To narrow down the start-uu issue, I would try to eliminate one issue. A fuel pressure gauge would verify this issue in minutes, but you could simulate by priming the fuel pump before starting the car by just cycling the key to run, bump the key to the start position just enough to turn the motor over for a brief second. Turn the key off. Repeat this 4 or 5 times. You should be able to hear the fuel pump run for a moment each time. If you then start the car and it starts and runs better, you likely have a bad checkvalve at the fuel pump draining the fuel back and it is taking a bit to refill the system on restart. It could also be leaky injectors dribbling the fuel out the injector(S) also. As I said, a fuel pressure gauge would be a much better diagnostic tool for this, but it's my guess it's fuel related.
