No I didn';t do it..The station did it..I asked for computer codes to find out what was wrong..Well they didnt even check to see the bulb for Check Engine was burned out...They put K44 and two treatments of fuel injection, charged me for a diagnosis and said you need a CAT..When I took it there I had gotten the NOX down to 1147 and they shot it up to 2600..Not fair..Help! What do I do now? Did they mess up plugs or anything else or is this temporary?....The gas is expensive to just try to run out to get rid of the cleaner...Renewed registration is due the end of the month..No where to take it off the road!..Oh my poor baby!

 

here is some crap i copied from another site to help you out. you really need to get the codes to be able to start. i would say its a bad o2 sensor or bad cat...or both. a faulty o2 sensor can often lead to a failed cat.

if you have a code for either one, start there.




What causes High NOX Emissions



Thousands of technicians have faced the challenge of bringing a particularly stubborn application into compliance for NOx emissions. High NOx readings are a clear sign of performance issues somewhere in the system. The question is, where?



Among the potential causes of non-compliant NOx readings are:
Misfire condition
Malfunctioning or improperly adjusted EGR valve
Failed oxygen sensor
Leak in exhaust tubing upstream of converter
Excessive carbon deposits in combustion chamber
Improper spark advance
Blocked coolant passage
Overly lean air-fuel mixture
Damaged cold air duct
Failed or malfunctioning catalytic converter
Corroded or damaged engine sensor electrical connections
Please note that while a failed catalytic converter will contribute to high NOx readings, the failure in itself may have been caused by some other upstream performance problem. In all cases, it is crucial to identify the root cause of the problem before blaming the converter.
Case Study
" I'm working on a 1992 3.1-liter Chevrolet that failed in the test lane. The results were very good for HC and CO—nearly zero—but it failed for NOx. The converter seems to be operating properly and the engine is running okay. What's causing the problem?"
Answer: Because this application, like many others, does not have an EGR adjustment, there's little the technician can do to "tweak" the engine's performance to bring it into compliance. It's clear the engine is running overly lean. A lean engine operating condition produces more NOx than usual, and the lean exhaust chemically interferes with the converter's ability to clean NOx (remember that excess oxygen is good for cleaning HC and CO, but bad for NOx).
There are dozens of potential causes of the high NOx readings, ranging from the relatively easy (detonation or failed oxygen sensor) to the extremely difficult and time-intensive (an improperly signaling MAP sensor). Because the engine is otherwise performing satisfactorily, the least expensive option may be to upgrade to a heavier duty converter such as a CleanAir "Premium" unit featuring increased catalyst for greater efficiency.

 

thank you so much for all of this information....Yes after we replaced the check engine light bulb we got key codes for map sensor..We also found a vacuum leak in wire to map sensor and changed that..The truck is running very well now.We had already changed the O2 sensor..before the fuel injector treatment and the NOX was still reading 1147. I heard that a cold engine was better for the NOx readings...Is that true?

 

bad news...After O2 sensor replaced,map sensor replaced,vacuum hose to map sensor,oil change and spark plug change, the NOX is higher than before...I love this Jeep but have never had anything give me so much grief!

 

then i would be replacing the cat. if they have pepboys in your area, they sell universal and magnaflow cats. they run 60-$100 bucks.

if you dont have access to a welder, just buy the appropriate hardware to clamp it in.

i have had at least 10 of my jeeps need a new cat to pass emmissions.