"robb" wrote in news:8L- dnY2qKZjT0rzXnZ2dnUVZ snipped-for-privacy@earthlink.com:
It is NOT "standard practice". You replace the sensor once it stops behaving as it should.
You're way high on HC and NOx on both years' tests, but the '09 CO of over
9% may be just a one-time glitch. It could simply be that the cat was insufficiently warmed up for both tests.You don't have EGR, so that won't be an issue. Have you ever checked the basic ignition timing? How old are your plug wires/cap/rotor/plugs?
Don't know. In my area you can have it tested any number of times until it passes. I think you have to pay for each retest.
If you randomly replace parts with no success you'll be out at least that amount anyway.
First thing to do is re-book the test, but at a different station. Make sure you're the very first car on the machine for that day. Take the car for a long drive (at least an hour) and time your arrival at the station with just enough time to hand in your key. TURN THE ENGINE OFF; DO NOT ALLOW IT TO IDLE. They should have the vehicle on the dyno within fifteen minutes at the outside. This will ensure the cat is up to temp and as efficient as it can be, which is critical.
IF the car fails again, even when properly prepped, THEN you start doing troubleshooting. The results from this test, combined with the results from the other tests, should be enough for a competent tech to daignose the car.