Emissions fail
#1
Emissions fail
Hi everyone!
I have a 99 Dakota with 275k miles. I failed emissions (HC 1.57, NOx 4.36) after using “Guaranteed to Pass” preemptively after failing 2 years ago. I tried adding 1 gallon of denatured alcohol to about 10 gallons of gas for the retest and failed again with similar numbers. Any ideas? As far as I know, the catalytic converter is original so I’m thinking about maybe replacing it but figured I’d ask for ideas here first.
Thank you for any ideas!
I have a 99 Dakota with 275k miles. I failed emissions (HC 1.57, NOx 4.36) after using “Guaranteed to Pass” preemptively after failing 2 years ago. I tried adding 1 gallon of denatured alcohol to about 10 gallons of gas for the retest and failed again with similar numbers. Any ideas? As far as I know, the catalytic converter is original so I’m thinking about maybe replacing it but figured I’d ask for ideas here first.
Thank you for any ideas!
#2
Any codes? You might have lazy/failing O2 sensors. Back in they day, I used to retard the timing so it would run lean and pass but nowadays it's all computer. I've got 320K and cats are still good... never failed emissions but was burning a bit of oil. Point is, I finally replaced valve stem seals and no longer burn oil, which might contribute to bad emissions.
#3
Any codes? You might have lazy/failing O2 sensors. Back in they day, I used to retard the timing so it would run lean and pass but nowadays it's all computer. I've got 320K and cats are still good... never failed emissions but was burning a bit of oil. Point is, I finally replaced valve stem seals and no longer burn oil, which might contribute to bad emissions.
I did do a head gasket job about 50k miles ago. The heads were totally reconditioned at a professional machine shop. I burn about 1 quart of oil every 3000 miles or so. That consumption has not risen much at all in the last 100k miles.
Concerning the O2 sensors...you’re saying they may be getting bad but not yet throwing a code? That’d be an easy fix if that’s the case. My neighbor has a computer of some kind (a bit better than a simple code reader but certainly no Snap-On). Maybe I’ll see if that gives any insight on O2 sensor output.
#4
I replaced mine last October, in an effort to improve my mpg. https://dodgeforum.com/forum/2nd-gen...-12-5-mpg.html
Can't say it did much, but I only paid 50 buck for a pair of Denso sensors on Amazon. You might want to try there if you decide to purchase. Also, that stuff you add to the tank, you do know you should go for a long hard drive when you put that stuff in? I'd say put at least 60-70 hiway miles on it (overdrive off to bring up the revs), then bring it straight to test center.
Can't say it did much, but I only paid 50 buck for a pair of Denso sensors on Amazon. You might want to try there if you decide to purchase. Also, that stuff you add to the tank, you do know you should go for a long hard drive when you put that stuff in? I'd say put at least 60-70 hiway miles on it (overdrive off to bring up the revs), then bring it straight to test center.
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#9
Yea many high end readers tell you a lot an can do a lot of things but a really great simple one I love is this bluetooth to phone reader an you can use many great free Apps too .It tells you the basics including current running information,02 readings , upstream, downstream , fuel trim,reset ecm, TEST readiness for tags[ saves retest cost $] an more..
Last edited by hidden1; 03-29-2021 at 12:56 AM.
#10