Barely passed smog check

[zer0c123]

My last smog check numbers have been really bugging me for some time. I just barely passed the NOX test. THe thing is that 4 years ago I replaced all the EGR parts. BPT, EGR valve, BPT pipe, EGR pipe, and the 2 gaskets. I pushed up on the diaphragm and the car stutters and almost dies. I'm assuming a hole in one of the vaccum hoses going to the egr or an exhaust leak would send the NOX numbers sky high in the 1000's range. I don't believe there is anything wrong with CAT, since I passed the other tested emissions will low numbers.

The only thing I did before the test was add 2 gallons of denatured alcohol to a 1/4 tank of gas. I don't really think it had any effect on lowering my emissions when comparing smog numbers form 2 years ago. I probably didn't run it long enough to the mix through my engine.

[Wc240]

alcohol burns faster and hotter than petrol. driving combustion temps/pressures up. couses higher nox. run it again without it if your lookin to diag anything your egr system isnt the only thing resposible for nox