So i was do for a Smog test,and was confident in the truck that will pass as the engine was running really good, in the last 2 years and only added about 4200 miles, also no check engine light ! in last 2 years , i have done smog in jan 2012 and passed ok.
Anyway , today not sure if this has something to do with it,i put some 91 grade gas ,about $25 and drove the truck about 8-10 miles then went to smog , and off course it failed.
They said that NO (PPM) is to high!
Also the smog guy said that my check engine light come on to the end of testing and then went off, he said most of the
time it happens when testing trucks because they are rear drive...but even with that light coming and going away
it still passed that function,so he said not to worry! I never from the last smog done had any check engine light!.
History of things done on the truck:
*12/21/2011 oil and filter where changed , miles: 235.200 (10-w40)
*2/10/2012 air valve was changed
*2/26/2012 spark plug wires and plugs where changed
*7/20/2012 oil and filter changed at 238.185
*10/7/2012 changed spark plug wires and plugs again as the old once start to crack
(changed under warranty at autozone)
*4/14/2013 changed oil and filter , miles 241.215
And i guess i am due for a oil change ,now or within 100 miles.
So now related to that high emission,what will be best to start? Engine runs okay,no check engine light.
The guy at the smog place said even if i burn all the 91 grade gas out and put back 87 unleaded , the emission may come
very little down but not too much and i still need to figure out ,what is causing this! He said to take a look at Cat,O2 Sensors ...
The truck is not smoking or anything.
Please let me know what will be your guys advice!
Thank you and appreciate your time to reply.
1995 Dodge Ram 1500 5.2L 2 Wheel drive.