Anyone?

 

bump

 

This is from the Magnaflow website:
Here are some other common causes for high NOx emissions:
•Misfire
•Failed Oxygen Sensor
•Leak in exhaust upstream of Converter
•Excessive carbon deposits in combustion chamber
•Advanced ignition timing
•Blocked coolant passage
•Lean Air/Fuel mixture

Not sure if this helps any.

Max

 

finally passed smog test! was lacking fuel and causing NOX to go high.. problem fixed after 4months of pulling hair im BALD! will ask the mechanic what he fixed exactly and will report back to help others will same problem hopefully. thanks all,,,,

 

So what did he fix to get it to pass??

 

So after replacing pretty everything under my hood that could contribute to NOX it ended up being my DIRTY fuel injectors. Mechanic used some solvent directly through the injectors disabling gas tank and it runs like new! I tried alot of fuel inj cleaners even the GTP (guaranteed to pass) stuff. Didnt work.twice. not even a new catalytic converter did the trick.
Was told carbon build is due to short trip driving. I only drive my xj 20 mins a day and it sits all weekend. I guess that why my 19yr old xj has only 72k!!