Erik the Red
NAXJA Forum User
- Location
- Northern california
Hi all,
My emissions testing is just going down the sink. First it was the EGR (which is now fine), now the test indicates the engine is running rich--CO is 1.61ppm at 2500rpm and .99ppm at idle. I searched previous posts regarding the cause of this problem and the following culprits have been suggested:
bad oxygen sensor
bad fuel pressure regulator
bad MAP sensor
assorted vacuum leaks
bad charcoal cannister
I'm not sure where I should begin to diagnose the exact cause of my problem, but I was wondering if one of the aforementioned possibilities is more likely than the others.
I can say that the oxy sensor in my truck hasn't been changed in nearly 140,000 miles (me bad). Also, and this concerns me, my exhaust manifold is leaking--probably a crack. Would this cause a rich fuel situation?
I don't have the money to replace everything willy nilly, so any suggestions on where I should start would be appreciated. Thanks,
Erik
88 Comanche 4.0L
My emissions testing is just going down the sink. First it was the EGR (which is now fine), now the test indicates the engine is running rich--CO is 1.61ppm at 2500rpm and .99ppm at idle. I searched previous posts regarding the cause of this problem and the following culprits have been suggested:
bad oxygen sensor
bad fuel pressure regulator
bad MAP sensor
assorted vacuum leaks
bad charcoal cannister
I'm not sure where I should begin to diagnose the exact cause of my problem, but I was wondering if one of the aforementioned possibilities is more likely than the others.
I can say that the oxy sensor in my truck hasn't been changed in nearly 140,000 miles (me bad). Also, and this concerns me, my exhaust manifold is leaking--probably a crack. Would this cause a rich fuel situation?
I don't have the money to replace everything willy nilly, so any suggestions on where I should start would be appreciated. Thanks,
Erik
88 Comanche 4.0L