I have a 91 Toyota Camry LE. It has automatic trans, 6 cylinders, and
180k miles. I have taken very good care of it since I purchased it in
- I recently measured its compression and it read 170 - 175 psi on all cylinders. I have faithfully changed oil every 3k miles since its birth.
Last week, I had my car inspected for emissions (in Texas) and I barely passed the HC portion of the test. Here are my pertinent results:
Pollutant At High Speed At Low Speed
Standard Reading Standard Reading
HC (ppm) 123 58 128 127 CO (%) .69 .16 .71 .24 CO2 (%) 14.5 14.3
NOx (ppm) 878 437 970 449
As you can see from the results above, I just passed the HC at low speed. I know that this usually means I have unburned fuel going out of my exhaust. I don't know what would cause this, especially since during the past year I have done the following:
- Changed plugs (platinum, Bosch plugs)
- Changed plug wires to Toyota OEM wires
- Cleaned EGR valve
- Changed PVC valve
- Changed fuel filter
- Changed distributor cap
Just before the emissions test, I changed oil and fuel filter. The air filter has 6k miles on it.
I checked by ear and with propance gas any possible vacuum leaks at the vacuum hose connections.
I want my vehicle to run as well as possible. I would appreciate some suggestions on what I might do next.