Failed Smog For 90 Celica GTS - Toyota Nation Forum : Toyota Car and Truck Forums

blackaneseazn · 05-22-2006, 05:09 PM

Hey everybody,
Need some help here for those familiar with smog check repairs. I brought my 90 Celica GT-S in for its every two year smog check. These are the results that showed why it failed. The non passing parts are the Functional Check, Emissions Test, and Ignition Timing: 5 BTDC. This was how it read out. Any suggestions for what needs to be repaired?

89CelicaGTTurbo · 05-23-2006, 02:03 AM

change your fuel cap. thats an automatic fail.

thousand_five · 05-23-2006, 02:15 AM

Do you guys think the emission place is bogging the engine down, by running at those rpms of less than 2000?

blackaneseazn · 05-23-2006, 02:39 AM

89CelicaGTTurbo, the fail is not for the fuel cap functional but rather the ignition timing: 5 btdc as the results read to the right for the ecs. I also forgot to mention that they put automatic transmission instead of manual. Perhaps this makes a difference? I'm not sure.

Doctor J · 06-01-2006, 01:07 PM

High NO suggests EGR system. .5% CO plus 120 HC calls for evap system. Replacing fuel filler cap gasket and checking EGR vac. modulator may help.
I also noticed from your previous posts that the car has rough idle.Open diag. box and measure voltage between Vf and E terminals, it must be close to 2.5 V. For more info., refer to Autoshop 101.com, technical articles by K.Sullivan.

blackaneseazn · 06-01-2006, 01:42 PM

The previous post I made about a rough idle was solved by replacing the timing belt. After my car died out and the belt broke, replacing it solved the issue. Now in terms of the smog issue, I also didn't mention that when I bought this car, there wasn't a secondary catalytic converter and I think that may be the culprit for failing smog. This was a few years back when I wasn't as aware about cars so I wasn't aware of this and figured all it needed was the main catalytic converter (located right by the engine). I'll probably start by having a secondary catalytic converter put in. According to the fat service manual, there isn't a oxygen sensor on the catalytic converter itself to be plugged in. Maybe it's just this year's model that applies to that. If the catalytic converter doesn't solve the problem, I just might need to dump some cash for a diagnostic test to see what is the problem.