blackwizard22

So my 94 lt1 with nothing but a cat back and an intake failed inspection for emissions. The readings were way higher than acceptable. What could be the culprit? Im thinking O2 sensors and injectors migth cure it. thoughts?

BlackScreaminMachine

iTrader: (17)

So you went on the emissions roller. what were your results and what were the limits.

Often with ODB1 cars you have to pass on the roller. I always put 93 octane with a bottle of rubbing alcohol, run a 180 thermo, change the oil/fuel/pcv filters, do a oil change. Make sure the car is NICE and hot. This should pass.

If at worse change the o2's and replace the CAT, a brand new unbroken in cat will always pass, with your minimal mods.

blackwizard22

nox should be 879 but it is 1770. hc reading was suppose to be 117 but it was 2632. my co% rating was suppose to be .65 and it is 2.03. any ideas?

Ralls

iTrader: (32)

I'd say need a new cat. Are you getting really bad gas mileage? Thats a sign of bad o2's. Everything is really high, probably running rich.

SincalT/A

iTrader: (16)

you have more than one problem.for sure cat h.c are way to high and possibly egr not working properly do to the higher flowing exhaust.you need to get the cylinder temps down that will help nox.do you have any other mods no matter how little.