1993 Toyota Corolla Failed Emissions - Check engine light o

Anything done to the car recently? Any tune-up? What rpm were those numbers at? Did you let the car run long enough?

RPM = 3179

Spark plugs and distributor cap (with wires) were done last year. I also had the resonator done last year. The car was running all day. Any advice would be greatly appreciated.

Thanks.

I'm not sure how long the rpm stayed at that, but I'm pretty sure you have a catalytic converter problem. That HC is way high for that rpm.

If the problem was the cat, why wouldn't my check engine light come on?

Thanks again.

Its obd1 car that has no cat monitor. OBD2 came out in 96. That is why they had to run the car for emmissions. If it was a 96 and newer they would plug into the OBD2 port and check for codes and make sure the monitors are set.

You might want to check to see if the O2 sensor is operating properly. You will also want to check for any exhaust leaks before the O2 sensor. Check the exhaust manifold for cracks as this would allow air into the exhaust system fooling the O2 sensor into thinking that the engine is running lean. Hope this helps.