'92 Previus Failing Emission Testing

Our '92 Toyota Previus, which we just bought as is, has failed the Ontario Emissions Testing and therefore is not able to be plated. It passed safety with no problems, but due to a small leak in the exhaust pipe at the catalytic converter, the catalytic converter was replaced prior to the first emission testing because the mechanic stated that they would automatically fail the emission tests because of this leak.

After failing the first emission test, I took the van to another mechanic who examined the vehicle and found that the Air Filter was completely clogged. The plugs and wires seemed to be in good shape, and he couldn't find anything else that could be causing the failures without doing a thorough diagnostic. The air filter was replaced, and gas line anti-freeze was added into the gas. The van was then taken for a 30 minute highway run prior to being tested again. Although the results were greatly reduced, and it only failed 2 tests as opposed to 4 previously, the van still failed.

The product, Guarantee Emission Pass was added to the fuel and the van was driven almost 400km on the highway before being tested once again, this time at another place. The van failed 3 tests this time, and the ratings were once again high.

Any suggestions as to what could be wrong before I spend the money for an emission diagnostic test? In doing an internet search I came across a note that recommended replacing the oxygen sensor when replacing the catalytic convertor, but this was not done when the mechanic replaced the convertor. I plan to call the mechanic to ask why this would not have been done when it is highly recommended, but hopefully others may be able to make other suggestions for checking.

BTW, the van is automatic with 230,000km, and the A/C is not working. Other than this the van runs excellently and seems to be in great condition.

Thanks! Tim

Reply to
Tim
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Not without seeing the emission results. Post the levels of NOx, HC, and CO and we'll help you out.

Reply to
Qslim

"Qslim" wrote in news:4282adfe$1 snipped-for-privacy@spool9-east.superfeed.net:

AND the limits you're required to meet!!!

Here's what that data looks like for our '99 Tercel:

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Reply to
TeGGeR®

Thanks, here are the Emission Tests results:

ASM2525 (25mph cruise) Idle

Date Item Limit Reading Result Limit Reading Result

1st Test HC (ppm) 52 240 FAIL 200 292 FAIL CO (%) 0.29 3.05 FAIL 1.00 2.00 FAIL

NO (ppm) 735 315 PASS N/A N/A N/A

2nd Test HC (ppm) 52 174 FAIL 200 80 PASS CO (%) 0.29 1.11 FAIL 1.00 0.48 PASS NO (ppm) 735 137 PASS N/A N/A N/A 3rd Test HC (ppm) 52 155 FAIL 200 261 FAIL CO (%) 0.29 1.29 FAIL 1.00 0.91 PASS NO (ppm) 735 317 PASS N/A N/A N/A

Reply to
Tim

Ops... newsgroup setting was for text. Here is the HTML display for my Emission Tests results:

ASM2525 (25mph cruise) Idle Date Item Limit Reading Result Limit Reading Result 1st Test HC (ppm) 52 240 FAIL 200 292 FAIL CO (%) 0.29 3.05 FAIL 1.00 2.00 FAIL NO (ppm) 735 315 PASS N/A N/A N/A 2nd Test HC (ppm) 52 174 FAIL 200 80 PASS CO (%) 0.29 1.11 FAIL 1.00 0.48 PASS NO (ppm) 735 137 PASS N/A N/A N/A 3rd Test

HC (ppm) 52 155 FAIL 200 261 FAIL CO (%) 0.29 1.29 FAIL 1.00 0.91 PASS NO (ppm) 735 317 PASS N/A N/A N/A

Reply to
Tim

I cant find your readings?

Reply to
Liberals=Angry Losers!

We'll, from the readings, I'd say you have an inop O2 sensor. (the one before the cat)

Reply to
Liberals=Angry Losers!

That is what I suspected, especially after reading that NOTE stating that when you replace the CAT you should also replace the O2 sensors.

Thanks, I'm going to have them checked the O2 sensors tomorrow.

Reply to
Tim

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