94 B3000 High NOx

[robert1225]

I own a 94 B3000 with the 3.0 L engine. I continue to have high nox even after a tune up, and replacing both O2 sensors. This truck does not have an EGR valve. It runs good. Any suggestions?

 

[TomB1269]

Oil change? Replace PCV valve? Any check engine light?

 

[robert1225]

Thanks for responding. I did oil change, tune up including pcv. I am not getting a check engine light. The only thing I have not checked is compression because power is not that good. Timing is set to spec.

 

[TomB1269]

Try some Seafoam to clear out the carbon build up..............

 

[robert1225]

I'll try the Seafoam, now if that reduces carbon buildup does that lower Nox readings?