Engine Performance problem
2001 Chevy Cavalier 4 cyl Two Wheel Drive Manual 74000 miles
P0420 is Catalyst Efficiency below threshold, bank 1
When the engine liight comes on, I erase the code with my code reader.
Sometimes I can drive over a hundred miles before the code comes on again, sometimes just 20 miles, if something was really wrong, wouln't the engine light be on all the time? Should I replace the heated oxygen sensor after the catalytic converter?
I replaced the manifold oxygen sensor with a Bosche,
I replaced the Catalyticconverter with a national auto OEM fit and it walked right through state inspection without any problems.
I cannot find any leaks in the exhaust system.
I pulled one of the spark plugs and it was clean.
I put a test light between the spark plug and the wire, the light was really strong, lit up the engine compartment! But it was not steady all the time.
To try and solve the probllem, I went to a higher ocatane gas and put Prestone fuel injector and fuel pump cleaner in the fuel tank and ran it down to 1/4 tank. The car always had good pickup, no hesitation.
When they went to ethanol in the gas, about 3 years ago, my mpg dropped to 26mpg, before I was getting 34 mpg.
So after running a tank of 89 octane from Sunoco, and the Prestone fuel injector cleaner, the darn engine light still came on. Most of the time it comes on after a pothole, sometimes not!
This is driving me crazy, because there are no leaks in the exhaust system, I have a strong spark, good pickup, and the wires appear to be plugged in tight on the oxygen sensors.
I hope somebody can help!
have the same problem?
Friday, March 5th, 2010 AT 11:35 PM