Topic: E-test failed! Help!

[BigBoi]

Hey guys,

I've been on this forum for quite a while but I have a question about my Jeep with the 4.0L. It's a '97 with 147K on it. I just bought it so this e-test is required to move it to my name. It looks like these were my results:

HC ppm Limit: 90 Reading: 31 PASS
CO % Limit: .50 Reading: .01 PASS
NO ppm Limit: 600 Reading: 2830 FAIL

So here's what happened. We replaced my catalytic converter, and re-tested it with these results:

HC ppm Limit: 90 Reading: 31 PASS
CO % Limit: .50 Reading: .01 PASS
NO ppm Limit: 600 Reading: 4089 FAIL

Then we added some liquid to remove the carbon in the engine, let it sit for an hour, then took it for a hard ride and re-tested it:

HC ppm Limit: 90 Reading: 31 PASS
CO % Limit: .50 Reading: .01 PASS
NO ppm Limit: 600 Reading: 1639 FAIL

My mechanic and I are running out of options. Can you guys recommend anything? Would wires and plugs and rotor potentially fix this issue? Is there a way to make it pass?

Thanks for you help!

[Jeffy]

I'll assume that cat is nice and hot before testing.  It means your combustion temps are too high.  This could be caused by a lean air/fuel mix, poor cooling, carbon, etc...  A vacuum leak could also cause problems.  Make sure the O2 is working, also.  Are there any modifications to the engine?  Open element filter, 4.0L TB, etc...  Are they just testing at idle, 1500/2500 rpm?  Are they doing a rolling test?

[/dev/null]

Well, I'd say you have a problem with your EGR system. Check your EGR valve, and other components.

From CA Dep. Consumer Affairs web site:
The vehicle's Exhaust Gas Recirculation system reroutes exhaust gases back through the intake manifold to lower engine temperatures and, in so doing, reduces NOx emissions. The EGR functional test is part of the two-speed idle (TSI) test, but is not necessary for the ASM (BAR-97) test because that equipment tests for NOx.

Also look here:http://autorepair.about.com/library/a/1f/bl605f.htm

Peter M

[BigBoi]

Thanks for your replies guys. The 4.0L doesn't have an EGR valve on that year (97).  The motor is completely stock which is why the mechanic (and I) are completely stumped. Would wires, plugs and cap help for NO PPM Limit?

[Jeffy]

I read what you previously said.  What was wrong with the Jeep be4fore you bought it?  To legally sell a running vehicle in CA it must pass a SMOG Inspection before sale.  The PO is supposed to have this done and I believe it  needs to be done within 30 days of sale.  If it's a 97' even with high mileage, I would think it should fairly easily pass the sniffer test.

I'd go back and recheck the PCM for any stored error codes.  Not all codes will trigger the CEL.  Check for vacuum leaks at the intake.  Warped manifolds aren't unheard of.  Although if it's on the intake side it should cause the idle to race to 1000rpm.  What's the operating temp of the engine?  Have you check the clutch fan?  The engine should run anywhere from 195-215*.  You might want to check the plug tips to see what they look like.  They are a good sign of how the engine's running.