1993 Toyota Camry LE 4 cylinder failed smog test does having the car in overdrive make a difference?

I dont know if it does any difference. I have a 1993 Toyota Camry and my overdrive was off. My test passed everything except for the NOx part, here are my results;

max" aveverage meas

490 175 1071 fail

511 162 993 fail

maybe it's just my egr, or cat, but is there anybody that knows what can be wrong? And also if a little water comes out of my tail pipe when it's cold when I first start it, can that mean a bad egr valve. My car past 4 years ago, probably when it had less than 150,000. Maybe the engine is full of build up carbon.

Answer:

The overdrive being on or off on your Toyota will not effect a smog check failure as the smog machine requires a specific RPM the smog technician must maintain during both drive test speeds; 15/25mph. Usually the 15mph portion will require 2nd gear and the 25mph part will require 3rd gear. Your Toyota's transmission will control the RPM automatically and properly if it is functioning right.

As far as the high NOx, your Toyota may very well trouble with the EGR system. It may have carbon build-up within the EGR passages, It may have a defective EGR valve (torn diaphragm), or possible a defective EGR valve transducer. High amount of carbon buildup could render anyone of these components defective. The only way to find out which part of the EGR system is defective is by a through hands on diagnosis of the system.

Before suspecting the CAT Catalytic Converter we recommend having the EGR system inspected. Also water coming out the tailpipe is not an indication of a bad EGR valve. Water from your Toyota's tailpipe is simply condensation due to cold, and should stop once the engine is warmed up.

posted by SmogTips Support