emission problems

[tdr racing]

I have a 1994 toyoa p/u 2wd reg cab efi.I just failed emission test and the carbon monoxide is high and also hydrocarbons, I was wondering does anyone have an idea on what may cause it to be so high.

[alltrac165]

AFM, TB, or O2 sensor would be my guesses
When's the last time you gave it a good tune up, plugs, cap, rotor, set the timing, etc.?

[ShawnM]

Im guessing converter. Of course anything is a guess without actually checking it out. May be multiple problems.

[tdr racing]

its a rebuilt motor with a new head and it has new plugs,air filter,rotor, cap,wires. just put the motor in like three weeks ago,timing is good.the only thing i did not is the o2 sensor is there a way i can test the o2 sensor ?

[ShawnM]

What was wrong with the old motor? Oil blow by will kill a converter and coolant in the combustion chamber will kill an O2 sensor. Keep in mind if its a recently rebuilt motor it will burn some oil untill the rings wear in a little.

[nmoen]

What was your O2 and CO2 readings. List all of the gas values listed on your vehicle inspection report. With those readings, I can steer you in the right direction for successful repair. Shawn does have a good point - What was wrong with your last motor? Oil, coolant, excess Hydrocarbons from engine misire can all cause CAT failure.

Neal

[crazycruzer]

If your results show that you barely failed, then all you have to do is put in high octane fuel and add in some octane booster and you should pass (unless you can find a station that sells 100 octane fuel).

[nmoen]

Octane booster will help NOx emissions only. Keep in mind, octane simply stated is resistance to burn. If you slow down your burn, you will increase your hydrocarbons. Does arizona test for NOx? What's your O2 and Co2 readings? I am a CA smog tech...I can help you but I need to know all the readings.

Neal

[tdr racing]

Here are the results in case you didn't get it in your own email. hydrocarbons (HC) is 2.16 applicable standard is 1.60, for carbon monoxide (CO) is 101.72 and the applicable standard is 20.00, and for oxides of nitrogen (NOX) is 0.09 and the applicable standard is 3.00 and as you can see I failed HC and CO and also just to let you know I passed the gas cap test and the pressure test. As for the other motor you guys were asking what was wrong with it it had a major valve leak and every morning when I start it it would throw out smoke and like I said everything is new the only thing I did not change is the O2 sensors and fuel injectors, but it has a new catalytic converter so the only thing I can think about is the O2 sensor. i appreciate your help. thanks.

[Tamme]

Hi everyone,

I have the same problem on my sedan Camry 91. It just fail the emisson test:

. . . . . . . . .Reading . . . . . . Limit
HC . . . . . . 02.10 . . . . . . . 01.20
CO . . . . . . 60.60 . . . . . . . 20.00
NOx . . . . . 00.11 . . . . . . . 02.50

Would you please give me some clues. Thank you very much!

[turbos17]

Try to retard (lower the timing) the engine a bit. The guy doing your smog test should be able to do it, if he is cool and wants to get his money. If not you are SOL! Good luck!!!

[Tamme]

Hi turbos,

Do you mean that I have to delay time point of combustion a little?

[Tamme]

Hi tdr racing,

Do you know what is wrong on your car yet ? If yes, could you let me know ? My car was also fail CO and HC. Thank you very much.

[tdr racing]

Hi Tamme, I have not yet found the problem I'm waiting for a reply from (nmeon)he is a smog tech and he said he needed my emission readings to help me out so as soon as I find out I'll let you know and try to help you out .

[Tamme]

Hi tdr,

I believe that my car problem due to MAF system. In my car, the MAF has an adjustment screw. But I do'nt know how to adjust it. If somebody know how to adjust it (procedure & specification) please let me know. Thank everyone.