1994 GC, 4.0L FAILED NoX
 

Hey guys wondering if you could help me out to pass the NoX part of my emission test

Limit was 715, and I scored 1165.

The numbers

HC ppm limit 52 reading 42

co% limit 0.28 reaading 0.21

NO ppm limit 715 reading 1165

high Nox is high combustion temp, but this year has no EGR so no dice there...

please someone help me who has had a similar problem and let me know what to do to pass!!

Thanks!!
Derek

Re: 1994 GC, 4.0L FAILED NoX
 

Hey DE,
I hear ya....Drive Clean (DC) is a tax grabbing, ill applied.....etc. You get the picture but it's there so we have to live with it.
When I sold my '94 with the 4.0, she had just passed DC with flying colours. What I did: Changed plugs, air filter and did oil change (filled up with the highest viscosity I could get (20W50 perhaps?)), filled up with high test gas, took her for a high RPM run (ran for a bit in 2nd gear up to ~4000 RPM) and took her straight to the test station not shutting her off while waiting.
Correct me if I'm wrong but I THINK I had an EGR that sat on top of the valve cover????? Oh, and make sure your high tension wires are in good shape as well. Changed oil back to 10W 30 shortly thereafter...
Hope this helps....Peter

Re: 1994 GC, 4.0L FAILED NoX
 

hey thanks for the reply, the only thing on top of my valve cover near the firewall is the PCV valve. 93-95 jeeps have no EGR, and instead use a 3-way catayltic converter. I just have a cheap $50 one on there now so its possible that it is only a 2-way converter, which wont help with lowering the Nox. I found a place that will sell me a direct fit converter for $99, so Im gonna slap that on, change the plugs and oil, put in some Ultra94 and give her a good run and hope for the best. The air filter is already new (2000km ago)

Ill post the new results when I get them,

thanks again

Derek

Re: 1994 GC, 4.0L FAILED NoX
 

Let us know how you make out...

Re: 1994 GC, 4.0L FAILED NoX
 

Dad gummed acronyms....Of course PCV not EGR......Grrrr...

Re: 1994 GC, 4.0L FAILED NoX
 

Hey Derek,
I agree with Savasa, get it on the road, with the fresh air filter, hi oct gas , oil change, and get that AWESOME STRAIGHT 6 running a little harder than usual for a while. Preferably on a highway and
then take it straight to the test location after that, keep it running too.
I had to do the same thing with my 93 jgc and it passed Vancouvers air car bull SH** . Albiet not
well in the last section but it passed. I failed it twice before not observing my recommended actions to pass. Hope it gets through. Let us know what happens.

Take care.

Re: 1994 GC, 4.0L FAILED NoX
 

If you can find "Seafoam" where you live throw a can of that in too!!! Most auto parts stores have it..