I have failed twice first time my hydrocarbons were 70ppm when they were supposed to be 60 while the carbon monoxide was at the pass limit of .32% and the nitrogen oxide was at 491ppm which was below the 700ppm limit. During the test mi car over heated as my fan switch wasn't working and I had been doing it manually. So I put a new 180 thermostat and put a 200-185 fan switch. So did the testing again my hydrocarbons came out 194ppm my carbon monoxide was .59% and my nitrogen oxide was 1151ppm so I failed all three area worse than before. I have noticed that my temp never reaches the 100 mark on mi dash with the
New fan switch and thermostat. Could mi car be to cold giving a rich condition or what
Else could it
Be?

 

tune up time?

 

Well I did an oil change put sea foam in the engine. HAs new spark wires I've done multiple 've learns on mi ebl. Just seems that mi car almost passed wen it was overheating compared to now failing badly but doesn't overheat. I know that if the engine is cold it will give a rich condition to warm it up. I'm assuming that cause mi fan seems to always be on its cooling my engine too much causing it to run rich.

 

I'd first check fuel pressure. For tbi should be 9-13psi. If it's too high the reg is inside the tbi unit. NExt I would monitor PIDs with a scan tool to see if everything is working correctly. Look at the spark plugs, if sooty they cold be too cold or the timing could be retarded if the AFR is determined to be good.

 

While factory guages are notoriously inaccurate, if it isn't moving past the low end, then yes, the car is running too cold, and subsequently rich.