Emission Test - fail

S

SC Cid

Registered User
Emission Test - fail - Help!!

Hey,

I went to pass my 1989 SC at DEQ today and it failed twice. The first test, image #1, shows I didn’t fail by much. As I was waiting in line for the first test I had the motor off and was coasting into the test bay, this took about ½ hour. Once at the bay door I started up the car and went in. After failing the first test I drove the car around for about 45 mins and returned to the test center for another test. This time, image #2, I had the car running the whole time as I waited in line. The second test reports a worse test than the first. Can someone give me some ideas where and what to check for?


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Is your car stock, what mods,what octane is the fuel your using..... we need more information to help you out.

If its mostly stock, I'd start by making sure your air filter is clean, the maf sensor is clean, pcv valve is good, good fuel filter...... the basic stuff first.

Frit
 
Hey,

From the reading the DEQ gave me it seems that a high NOX reading is caused by too much air in the mixture, lean, or bad CAT. Which causes the internal temps in the chambers to run too high. This would make sense since my first reading was almost passing, this reading was done after the car sat in line not running. The second test was after the car was good and warm and running in line. As to the mods, there are none that I know of. Octane is one above regular, I use premium. This car is a californian car and is now in oregon. Should I be looking at the supercharger as to the air flow?
 
Running hot?

NOx's are produced when the combustion temp are over 2500 F. Things that can cause this are
1) Lean mixture: Is the fuel system in good shape? How about those O2 sensors? They don't live forever.

2) Retarded timing: Your probably safe there.

3) Carbon buildup in chamber: Not likely the problem.

4) Overheated engine: Is it running hot? When was the coolant dumped last?

5) Failure of the EGR: If your car has an egr make sure it is okaly dokaly.

6) Old beat up cats: Even if there are other problems new cats will let you pass most times. But the underlying problem may still be there. If the car has ever blown hg's the cats have probably failed from the coolant that was run through them. At 116,xxx miles it is possible that they are just worn out.

Good luck and let us know how you do.
Anthony
 
I had NOX problems when I tested. I ran some Seafoam through a vacuum port, pulled the Octane plug and put in a bottle of octane boost. All cheap and easy and cut my NOX by half. Passed the second time.
 
Hey,

After the second test I dumped some emissions cleaner in the tank and filled yer up with regular. I put 200 miles on the car over the next two days just driving around. Today I filled yer up the 89 octane went back to DEQ for my thrid test and failed it by a slim margin on the NOX reading. While inline at the DEQ a mechanic called me back on my accumulator problem and said to bring the car by his shop so he could look at the brakes. While there I said I had failed my test and showed him the test report. Without even thinking the mechanic, stan, pulled out a bosch block and said this is the plug for the octane setting. Then he said since I was so close on my test that should get me through. Then he pointed to another bosch plug and said if you fail the next time take this shorting block and you should pass. I said what was this on for he said it takes your timing back to base without any advance. I said ok and drove off. I passed with the first bosch block out but just barely.

Stan is going to replace my motor mounts for 300.00, that's with fluid mounts. I thought that was a deal? what do you guys think?
 
SC Cid said:
I passed with the first bosch block out but just barely.

Stan is going to replace my motor mounts for 300.00, that's with fluid mounts. I thought that was a deal? what do you guys think?
Click to expand...
Do you have your Nox readings before and after? It'd be nice to know how much of a diff the octance plug makes. Of course the plug is a cheat, to fix it for real, you'll need to do something about the EGR such as clean or replace. Wonder why he called it a bosch block.. the books call them the octane plug and SPOUT test shorting plug.

300 is a great deal for engine mounts.. I presume he's going to do them on a lift by lowering the subframe. That's the only way a pro mechanic can get it done and not loose $ on the deal. The fluid mounts are the same as the OE and can be expected to last about as long which is about 90,000 miles.
 
Hey,

Here’s the readings....

Test #1 - car cold at test.
THC 0.86 NOX 3.72 CO 9.8

Test #2 - car warm at test
THC 1.34 NOX 4.72 CO 16.1

Test #3 - with emissions cleaning additive ran 200 miles
THC 0.88 NOX 3.93 CO 13.8

Test #4 - with octane plug pulled
THC 1.17 NOX 3.59 CO 12.2

Passing marks: THC 2.00 NOX 3.70 CO 32.0
 
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