Fail my emission today: help

[quangtran89]

I have a 86 mr2 with a 1.6 4a-ge
Went to get my emission test and these were the result.





So far I have replace air filter, wires, plugs, cap, rotor, and oil change . I also clean out the throttle body a bit. It was nasty thick black gunk. The difference between yesterday and today driving was like day and night. Car feel and shift better. The car is also idling a little to high I think. It's idling at 1800 when frist crank and go down to 1200 after it's warm.

Any help would be appreciated

[Jason.MZW20]

Your NOx is off the charts high. That points to a faulty EGR system and possibly a bad catalytic converter.

High hydrocarbons (HC) can indicate a bad catalytic converter as well, but it also has a lot to do with the overall health of the engine. If the air/fuel mixture isn't burning correctly, you usually get increased HCs. Slightly advanced timing can increase HCs as can vacuum leaks.

Replacing the catalyst with an OBDII catalyst will bring all of those numbers WAY down, but you still need to fix the EGR system.

[quangtran89]

So you think a new egr and cat will lower it down?

I'm also thinking about a rebuild and use those receipts toward my repair waiver to exempt emission.


Forgot to mention, the car has about 240-250k miles. The speedometer stop working in 2004

[quangtran89]

Just bought parts for my rebuild. Gaskets, pistons, rings, timing belt kit.

Should I get a new EGR valve or clean the old? The Cat will be replace.

[Jason.MZW20]

Originally Posted by quangtran89

Just bought parts for my rebuild. Gaskets, pistons, rings, timing belt kit.

Should I get a new EGR valve or clean the old? The Cat will be replace.

Good stuff.

You can soak the EGR valve in a strong solvent for a day or so, and then check to see if the valve moves freely. If it's vacuum modulated, make sure that works too, otherwise the EGR system won't function as well. It'll be up to you if you want to replace those parts.

Are you gonna use an OBDII cat?

[quangtran89]

What's the different. I was thinking about taking the emission again, but I also thought about just leaving the car till next year to register so and not need emission because it'll be 25 years old.

edit: Just looked up price for an egr valve, that junk is expensive.....

[not12listen]

just in the sense of doing the easy and inexpensive things first, i would recommend replacing all of the vacuum lines.

its about $15 worth of line in total from your local auto parts store, and it can have a huge impact.

also, one other trick is to get the engine SUPER HOT prior to getting to the smog shop. this ensures that the catalytic converter is at its optimal working temperature. so... hop on the freeway and keep it around 5000rpm for 10 minutes, then go directly to the smog shop. do NOT shut the engine off.

keep it running and have them test it right then...

catalytic converters only do their job when they're scorching hot.

[quangtran89]

The rebuild didn't go as planed. Lazy friends keep postponing. I decided to buy another motor. Some 4age, but not going to swap it just yet. Going back to School next week.

I manage to get my NOx down by half and the HC to double digit. But I am still off about 300 on my NOx ppm. So Close...

So far I replaced the cat, replaced some vacuum lines (no vacuum leak). Adjusted the idle, was able to bring it down to 900rpm now.




Going back for a retest tomorrow, I adjust the timing. It was too advanced. Retarded 10 degree. Also cleaned the intake manifold a bit, it's still very dirty. A lot of build up.

[quangtran89]

I passed! Had to adjust the timing and used some octane booster. NOx allow was 1440, my reading was 1433. Thank goodness it's the last year.

[MR2Jedi]

Good deal! I know your happy.

[PhatRoyale]

Sounds like what I went through with the Corolla this year.... emissions is a pain.

Congrats on passing though.

[mr2tim]

You mentioned the car idled high before you got into it?

Have you set the TPS per the BGB? (It has nothing to do with that idle screw BTW.)

BTW come on down, here in Florida the CITIZENS voted to end our silly ass passenger auto inspection fiasco.

[quangtran89]

The car idle at 900-1000 now. At first I was only able to bring it down to about 1200 by turn the screw.Then after adjusting the timing I was able to bring the idle down to 700, but at 700 the car was shacking too much so I brought it up to about 900.

I almost kill my car today. Took a sharp corner and lost control. My lower control arm and strut rod got bent causing my front passenger wheel to be push back 2". Almost lost my dream car today...Glad it's nothing major.

[mr2tim]

Here's a section of the parts list you might want to peruse:



I feel for you dude. I'm from Detroit and it took me 2 years to feel comfortable on the track with these mid-engined cars. Having throttle induced oversteer is a must.

Maybe I can help?

Tim
mr2tim

Originally Posted by quangtran89

The car idle at 900-1000 now. At first I was only able to bring it down to about 1200 by turn the screw.Then after adjusting the timing I was able to bring the idle down to 700, but at 700 the car was shacking too much so I brought it up to about 900.

I almost kill my car today. Took a sharp corner and lost control. My lower control arm and strut rod got bent causing my front passenger wheel to be push back 2". Almost lost my dream car today...Glad it's nothing major.

[scarney1988]

I am assuming there is a lot of buildup on top of your pistons. Not unusual for high mileage cars, however it will increase compression and thus increase NOx output. If you have the head off take a look, or try running some top engine cleaner through it (although i do not know how effective these things are. If you have the head off just scrape it off the top of the pisons. Good luck.