# 87 Maxima emissions test failed, code 44



## aruef (Jun 25, 2005)

My 87 has 192k miles, runs great, new MAS last year, new fuel filter recently, well maintained, failing on low speed test - HC=193ppm (limit 162) and NO 2872% (limit 1227). ECU code 44 = all ok, right? I've added octane boost to premium gas and had it tested warmed up. O2 sensor test (per Haynes/Chilton manuals) checks out - 8 green flashes in 10 seconds at 2,000rpm. Any suggestions?


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## brianw (Feb 25, 2004)

Replace your catalytic convertor.


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## aruef (Jun 25, 2005)

New catalytic converter might work. I forgot to mention the car passed easily on the high speed portion of the test and failed on the low speed. If the cat was needing replaced, wouldn't it fail on both? Or would the higher volume of exhaust push more HC/NO past a weak cat? Also, is new the only way to go? I've heard that is an expensive part.


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## brianw (Feb 25, 2004)

Cat is probably failing, since *both* HC and NOx are high.

NOx is pretty high, I don't know if your car has an EGR system, but if it does, try cleaning the tubing for the EGR and the valve itself. I'm not familiar with your 2nd gen so I can't offer specifics, nor do I have FSM for it...

High HC potentially means crap in the TB or dirty fuel injectors. Bad O2 sensors as well.

But since your car fails both and by large margins I would suspect a bad cat. Pick up an aftermarket one (any muffler shop should carry 'em), shouldn't be more than $100-200 installed depending how much work they have to do to install it.

Also, check your timing. It should be at stock.


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