emmission test failed

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Feb 15, 2008 | 08:25 AM

B Dobz

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emmission test failed

1990 f150 with 302 automatic trans failed the emmision test and said my nox was to high at 1425 and normal is around 1100 I have no cel lite on and want to know what would cause this to be high?would old gas that has been in the truck for atleast a year be the problem?any ideads?thanks

Feb 15, 2008 | 08:39 AM

Conanski

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From: Ottawa, Ontario

Possible bad converter, are they original?

Feb 15, 2008 | 08:52 AM

mprice

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From: Chicagoland

High NOx could also be from combustion temps that are too high. You might check out the EGR plumbing to make sure it isn't plugged and the valve is operating. A lean burn will also run hot so you might check your fuel pressure and injectors to make sure you are getting all the fuel you need.

Calvin

Feb 15, 2008 | 09:50 AM

B Dobz

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yes the converters are from the factory,how would I check the egr to make sure it is working right?I was hoping it was bad gas.I must say the truck runs great.

Feb 15, 2008 | 10:41 AM

B Dobz

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just found out from my son that he had put old gas that was mixed for a outboard motor at 50-1 in my truck to get rid of it!I guess that don`t help much.