Damn Jeep failed the smog test! That came a total suprise....

My '98 Jeep Cherokee with 83,000 failed its smog test today and I truly did not see that coming. It has been running great, gas mileage is about what it has always been, maybe a little less as it has seen more stop and go city driving but nothing that would make me really concerned...

ANYWAY, it failed on the NO (PPM) section at 15MPH. The MAX is 522 and I came in at 660! At 25MPH the MAX is 775 and I passed with 237. Everything else looks great... so where should I start?

%CO2 @ 15MPH = 14.9 %CO2 @ 25MPH = 14.9 %O2 @ 15MPH = 0.1 %O2 @ 25MPH = 0.0

HC (PPM)

MAX @ 15MPH = 53, I'm at 42 MAX @ 25MPH = 37, I'm at 37

CO (%)

MAX @ 15MPH = 0.67, I'm at 0.05 MAX @ 25MPH = 0.81, I'm at 0.04

NO (PPM)

MAX @ 15MPH = 522, I'm at 660 (fail) MAX @ 25MPH = 775, I'm at 237 (pass)

What's even worse is that after calling my mechanic he said he can't do any of the work and that I have to call a repair station... Geez California really sucks....

Doing a little research makes me think I might need a O2 sensor, its original or a catalytic converter... original too. Anyone have any clues on where I should start or should I just go find somebody to do the work?

Thanks as always....

-- Taylor

'89 Audi 200 '03 Audi S6 Avant '98 Jeep Cherokee Sport

Reply to
Just Taylor
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In news: snipped-for-privacy@wilhelp.com, Just Taylor from was injured because:

| My '98 Jeep Cherokee with 83,000 failed its smog test today | and I truly did not see that coming. It has been running | great, gas mileage is about what it has always been, maybe a | little less as it has seen more stop and go city driving but | nothing that would make me really concerned... | | ANYWAY, it failed on the NO (PPM) section at 15MPH. The MAX | is 522 and I came in at 660! At 25MPH the MAX is 775 and I | passed with 237. Everything else looks great... so where | should I start? | | %CO2 @ 15MPH = 14.9 | %CO2 @ 25MPH = 14.9 | %O2 @ 15MPH = 0.1 | %O2 @ 25MPH = 0.0 | | HC (PPM) | | MAX @ 15MPH = 53, I'm at 42 | MAX @ 25MPH = 37, I'm at 37 | | CO (%) | | MAX @ 15MPH = 0.67, I'm at 0.05 | MAX @ 25MPH = 0.81, I'm at 0.04 | | NO (PPM) | | MAX @ 15MPH = 522, I'm at 660 (fail) | MAX @ 25MPH = 775, I'm at 237 (pass) | | What's even worse is that after calling my mechanic he said he | can't do any of the work and that I have to call a repair | station... Geez California really sucks.... | | Doing a little research makes me think I might need a O2 | sensor, its original or a catalytic converter... original too. | Anyone have any clues on where I should start or should I just | go find somebody to do the work? | | Thanks as always....

Get a multimeter an test the O2 sensor before ploncking down the $$$. Your service manual should have the values for it. Keep in mind that if it does pass on a multimeter, it may still be bad. There is a heating element in there that can be tricky to test....watch your fingers...

Reply to
Joseph P

Reply to
L.W.(ßill)

Just one out of three... last tune up was exactly at 60,000 and I did the oil filter myself last Friday. The service station was about a mile from my home. I let the Jeep idle about 10 minutes as I waited for the grease monkey to start. I pretty much did what I did two years ago and passed with flying colors...

I guess going for a long drive and re-testing @ $45 would be better than shelling out $80 for a diagnostic... then again if it fails again I'm out $45 :) I'll try that tomorrow, thanks!

-- Taylor

'89 Audi 200 '03 Audi S6 Avant '98 Jeep Cherokee Sport

Reply to
Just Taylor

On Mon, 10 May 2004 15:50:10 -0700 in rec.autos.makers.jeep+willys, Just Taylor wrote,

For excess NO you should start by making sure the EGR valve works.

Reply to
David Harmon

Reply to
L.W.(ßill)

Did I miss something here? My 88 XJ with electronic fuel injection uses an EGR system. Manufacturer did phase that out in the 1991 XJ models though. Must be a different year or model I guess that the OP is talking about. later, dave AKA vwdoc1

Reply to
dave AKA vwdoc1

Reply to
L.W.(ßill)

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