Originally Posted by ol Dusty
pretty sure the only eg with a EGR was the VX model. did you change your oil first? how about plugs and wires? fuel filter ever been changed? air filter? how far over were you before and after the cat was changed and what cat did you use? read up on DIY seafoam and maybe also check your timing if your too advanced/retarded that can cause high readings also if your car passed the HC and CO well, and it a Honda I'm sure it did, have the heater on full and run the car cold. NOX is created by the mixing of HC's and O2 at higher temps. also just to be safe check your PCV valve while your at it. it's in the hose that goes from the IM through the middle runners of the IM, that's the PCV it self then the hose continues down to a black box hiding under the IM. Good luck.
The numbers went up after I installed the hi flow cat.
everythnig else is perfect.
Timming is backed off to 18.
Oil was changed, plugs are fine, wires are fine, PCV is fine.
Dont think o2 sensor has ever been changed.