Failed smog high NOX - Toyota Nation Forum : Toyota Car and Truck Forums

..damn.. · 12-29-2008, 06:13 PM

Ok my car passed everything but the NOX i am thinking egr valve or cat? what do you guy's think?

Also last night as i was driving back home my check engine light came on?

91 Coorolla dx 3sp

***new echo owner*** · 12-29-2008, 08:40 PM

What is the code? Maybe it has something to do with the NOX problem.

N.E.O.

..damn.. · 12-30-2008, 12:59 AM

Quote:

Originally Posted by new echo owner

What is the code? Maybe it has something to do with the NOX problem.

N.E.O.

I can hook up an obd1 code reader?

***new echo owner*** · 12-30-2008, 01:12 AM

This is for a Camry, but you car has similar setup to check for codes, P23 to 27: http://www.camrystuff.com/manuals/Gen2/EFI.pdf.

N.E.O.

..damn.. · 12-30-2008, 02:06 PM

Ok it's got a code 21...

You know how hard it was to find out what code 21 mean's!...lol I guess it's the O2 sensor.

***new echo owner*** · 12-30-2008, 09:15 PM

Code 21 is indeed for the oxygen sensor signal problem; however, it doesn't usually affect NOX emission though.

N.E.O.

Rookie_One · 12-30-2008, 10:13 PM

maybe he should check the whole exhaust line and the intake?

Duy- · 12-30-2008, 11:42 PM

Quote:

Originally Posted by ..damn..

Ok my car passed everything but the NOX i am thinking egr valve or cat? what do you guy's think?

Also last night as i was driving back home my check engine light came on?

91 Coorolla dx 3sp

most likely egr valve unless your car uses a 3 way cat.

***new echo owner*** · 12-31-2008, 12:02 AM

Forgot to ask, what are your test results?

N.E.O.

..damn.. · 12-31-2008, 01:09 AM

Ok installed new OEM o2 and the code went away..

Well my smog result's passed very very clean except the nox that failed. Now sometimes the car has a slight stumble at idle when warm im thinking it may be the egr?

***new echo owner*** · 12-31-2008, 07:24 AM

Have you check the timing?

N.E.O.