Toyota 22re and California smog

So 2 years ago my truck barely passed smog, The max number was the number measured for HC running on the dyno. Well this time around the funky punky pickup 1994 toyota pickup 22re with 237k miles didn't pass HC on the dyno at either 15mph or 25mph. The numbers range from approx. 20-30% higher than passing. After failing the smog test I changed all the vacuum lines, air intake boot, afm seal, crankcase vent line, cap and rotor. I just want to see if there is anything else I should check before going in for a retest. I'm thinking about putting a gallon or two of E85 in the tank to see if that might help a bit. I have no idea if the EGR is serviceable, I figure it might be gummed up or something.

I also tested the AFM and it seemed to pass the static and dynamic tests.

Any help or suggestion to lower the HC is appreciated. I have until monday to get this damn thing retested so any and all suggestions are appreciated.

Is it eating or burning oil? That's usually your HC failure. Other stuff you can do includes taking the EGR off and spraying it with carb cleaner to de-coke it, running Marvel Mystery Oil through an intake vacuum line to break up carbon on the intake valves, and having the injectors cleaned (take them out and bring them to a NAPA or something, the stuff you pour in a tank does jack crap). You may have to bite the bullet for a catalytic convertor, too.

PS - E85 will hurt you, not help you.

I would suggest that you post the actual test results. Then maybe someone can pinpoint an area to work on, like the Cat or something. Doesn't a high HC mean the cat isn't cat'ing?

High HC is typically cat or O2 sensor. Depending on what the other num,bers are, there are sometimes things you can do, like advancing the timing.

It doesn't burn any oil even at 5000mile oil changes.

TEST/%CO2/%02/HCmax/HCmeas/COmax/COmeas/NOmax/NOmeas

15mph/14.9/ 0.2/ 95/ 110/ 0.52/ 0.34/ 386 / 263

25mph/ 14.9/ 0.2/ 60/ 89 / 0.63/ 0.33/ 564 / 218

We'll see if this works, I need the spreadsheet app.

I'm thinking maybe the O2 sensors are cooked given that I think they are original.

Any suggestions are appreciated.

O2 sensors and Cat are the usual culprits.

A decent way of testing the cat if you have the right kind of thermometer (I think the IR kind like you're use to check race tires are supposed to work well) is to measure the temp pre and post cat. If there is not a temp bump, it means your Cat isn't working properly.

Also of note is that CA seems to tightening up the tests on older cars. They want the cars to run the tests in higher gears, which brings the RPMs down, which helps them fail.

I talked to the tech last time, and he is trying to get into some "special status" with the state and to do that he has to start getting tougher on older cars.

If you can find a smaller set of rear tires for the car, that might help. I have to smog a carburated 87 B2000, and it ain't easy, and it has a rebuilt engine! Getting the car as hot as possible before the test is also a good idea (might not be that easy this time of year, especially in San Fransico... but you do have the hills...)

OK I did do the catalyst temp test last week with my IR thermometer and the temperature is 30F(330F in 360F out) higher after the catalyst than before so I'm thinking the O2 sensors might be done. I think I'm going to change them and see what happens. Oh these sucker look like they are on there too, oh boy!

Wish me luck, I don't really want to change the catalyst as they aren't cheap anymore. A catalyst used to be 120$ now the cheapest you'll find is 250-300$ and it is illegal to sell a used catalyst.

I'll keep you folks posted and thanks for the suggestions.

Move

benzbaronDaryn wrote: It doesn't burn any oil even at 5000mile oil changes. TEST/%CO2/%02/HCmax/HCmeas/COmax/COmeas/NOmax/NOmeas 15mph/14.9/ 0.2/ 95/ 110/ 0.52/ 0.34/ 386 / 263 25mph/ 14.9/ 0.2/ 60/ 89 / 0.63/ 0.33/ 564 / 218 We'll see if this works, I need the spreadsheet app. I'm thinking maybe the O2 sensors are cooked given that I think they are original. Any suggestions are appreciated.

I hate to be the bearer of expensive news, but I don't think your O2 sensors are as bad as your catalyst. The way I see O2 sensors fail, you normally get HC/CO high or NOx high, but not all high at the same time. Granted, you are running slightly more rich with the HC, but the NOx is elevated, so...

Can you find a high performance, universal fit catalyst? I've seen some advertised, but...

IF you can monitor the voltage, can you look at the O2 sensor volts? That may give you a better indicator that it's the culprit, but I just don't think it's the core.

But, I sure hope I'm wrong.

I ordered a set of O2 sensor so I'll see what happens after that, I guess if that doesn't solve the problem I'll probably need a new catalyst. I know the O2 sensors have over 100k miles on them so I figure it couldn't hurt, hate to eat 120$ if I'm wrong though.

Thanks for the tip Alfa, no performance catalysts in Cali, you basically get what they give you. If I end up spending 500$ on the pickup I guess it is probably money well spent. My mercedes gets 2 smogs or about 4 years out of a catalyst before needing replacement so if the truck only got 18years I'm a bit disappointed.

I'll keep y'all posted and thanks for the tips.

A small vacuum leak will clean up hydrocarbons, works wonders for my caravan