95 Chevy tahoe

[Ayden07]

Good afternoon members,

I am needing some help to try and pass my inspection, but I got a fail in the category

NOx (ppm)

Hi speed emissions results Low speed emission results

Standard Current reading Standard Current reading
1206 1379 Fail 1301 1330 Fail

Not sure what part or part to replace to help pass in this category! I passed in all the other category's! I've tried to take it to autozone to hook it up to there code machaine but they don't have one because my truck is to old they said. Please help! Thanks

 

[SunlitComet]

Lean running engine and/or malfunctioning egr system. There are scanners that read your truck by a shop would likely have them. You have an obd1 diagnostic system.

 

[Happy]

I recently worked on a 95 Tahoe

It needed a O2 Sensor, EGR Valve, and a Catalytic Convertor.....runs like a champ now