Maximums allowed: HC: 0.80 CO: 12.00 NOX: 2.00

1st Test: HC: 0.68 CO: 6.34 NOX: 2.30

After the first test failing due to high NOX i removed the Hypertech tuning and ran it through again.

Retest results: HC: .63 CO: 5.82 NOX: 2.02

Almost passed on the retry but still high NOX.

Any suggestions? The guy a the testing center says its most likey NOT the Cat, or else the other numbers would likely be higher as well.

 

EGR valve still on the engine?

high NoX is usually from a failed EGR system

 

Yup - might be pluged up with carbon.

Otherwise is it running hot? Too much timing (but you set it to stock anyway), bad cat, possibly carboned up pistons and combustion chambers. Make sure to use premium gasoline - that will help too.