Passing california emissions test
 

I recently purchased a 1996 T4R SR-5, and I'll be needing to pass the super strict California smog inspection before I can get my license plates. How strict is California ? They will 'fail you' for a gas cap that does not pass a pressure test.

I could use some advice about how best to insure I'll pass.

What have I done so far ? New spark plugs, new battery, new air filter, oil change and filter with a heavier oil 10W-40, fuel injection cleaner run thru gas tank, checked all hoses for any possible vacuum leaks, cleaned PCV, cleaned Mass Air Flow with CRC MAF cleaner. Will be pouring Lucas "deep clean" fuel treatment into a full tank and running the T4R at hwy speeds for 150 miles before the inspection.

Currently, I do NOT see any visible emissions from the tail pipe. The idle is running a tad high, about 1,200 rpm.

Any suggestions gratefully appreciated. Thanks, guys. :hello:

I would not necessarily say California is "super strict", it's pretty easy to pass smog, you just need to make sure your vehicle is running well and no major issues are present (which it sounds like there may be).

If your fuel tank can't hold vapor pressure, you will probably not pass smog, so that will likely need to be addressed (sounds like all you need is a new gas cap, should be easy to replace). If you have any check engine lights (or have cleared any check engine lights in the past ~50 miles) you will not pass smog.

If your engine is idling at 1200 rpms at operating temperature, something is wrong. 1200 rpm idle seems about right on a cold start, but idle at operating temperature should be ~650 rpms. It could be related to your vapor pressure issue, but most likely your Idle Air Control Valve assembly needs a good cleaning.

Your fine as long as you dont have the check engine light on. I failed before because my light kept coming on. the guy said I passed all the tests but said they check engine light( that I had cleared before I went in) was still in the computer. Said to go drive a while and then come back and it should be cleared if it didnt come back on during the drive.

There are plenty of places that will do a pre-test to see if there are any problems. Your idle (if that is your warm idle) is a problem. Other stuff... just get a pre-test and see.

-Charlie

The engine check light is not on. I do know for certain that it does work because it lights up when key is in ignition position and the engine is NOT running.
I have no reason to believe that the gas tank cap is bad but I'll replace it "just in case". Can't be too careful.
When I replace the battery, I read that it erases all of the previous computer info. Is that true ? If so, I read that 150 hwy miles will reset it.
I'm certainly no mechanic. I used to be able to do most anything on older cars back 50 years ago, but now with all of the emissions controls and fancy electronic stuff, I feel like a novice. Is it easy to turn down the idle with basic tools. If so, any tips gratefully received . Thanks guys.

Here is a vid about cleaning and checking the IAC valve.

YouTube

Since its older then a 99 you will need to have it tail pipe tested and obd2 check done to pass CA smog. Fix the high idle issue and you should be set. Warm it up before you have it tested.

Back in the day (4 or so years ago) I had my smog guy fail my miata. He said my emissions were to high. Ok I replaced my cat (18 year old cat) retested and failed again. I was pissed at this point so I came back (changed nothing) and retested. Well it failed, but this time I watched what he was doing. Over revving and over loading (lugging) the engine at the low and high speed tests, passed at idle. So I told him to do the test properly and it passed flying colors. Never went back to that place again.

Anyways hope the vid helps you out.

I haven't had a Toyota gas cap go bad yet (my '89 Camry still has the original cap and passes the tests). Certainly don't replace it with any crap from a parts store.

Replacing the battery will reset the computer. It is not just '150 miles' - it is a list of certain criteria for each specific type of emissions feature (evap, cat efficiency, etc.). Generally a week or two of 'regular' driving will do it. It WILL be more than one drive. And it will require at least a few full cold to full hot cycles. Any smog shop can do a quick plug-in and check if the emissions readiness monitors are set.

Seriously though, stop worrying. Drive it, take it in, it should pass just fine. If you fail, come back with your report and we can help diagnose. If you have any concern at all about tailpipe emissions, you can do a few tricks to help it along - even as simple as just keeping it running when you get to the smog shop and driving at least 5 miles before you go there.

-Charlie

Like everyone has said if the truck is in good shape, passing is not that hard.

I usually do a freeway run with mine on the way to the test and get the cat hot as ****
Get it HOT!
Premium gas helps. IDK I always run the cheap stuff.

Also- If your truck is from out of state, tell the smog guy. It becomes a federal smog and not a CA smog (easier) My truck is OOS has a replacement cat which can be an issue. Tell them you're from somewhere else and they might give you a break. My guy does, that's why I go back to him.
Good luck.

2TH4ist, thank you for the video, but it WAAAY over my head and he said at the beginning , "Do this procedure at your own risk". I'll give it a pass. Took it out for a short drive to warm it up and my idle speed was registering 750 rpm.

Additionally, I definitely will be driving it at hwy speeds before the test and I'll keep it running during any wait.

You are on the right track, it would be good if you had a scan tool to see if there are any markers, the fact that you replaced the battery could make for the dreaded Catalyst not ready. I just had this with my son's 2000 and I did have to replace the front Catalytic converter with the CA legal replacement for $250. Once we did that only the EVAP monitor showed not ready, but that is allowable in CA so it passed no problem. But you should just drive it a bit and have it tested, like @phattyduck said " Seriously though, stop worrying. Drive it, take it in, it should pass just fine. If you fail, come back with your report and we can help diagnose. If you have any concern at all about tailpipe emissions, you can do a few tricks to help it along - even as simple as just keeping it running when you get to the smog shop and driving at least 5 miles before you go there. "

Good luck!

Could you please be a tad more specific about that business of over-revving/lugging the engine ? Like, how do I know that he is messing up the smog test ? What should I watch for ?

Stop worrying, take it in. If my >30 year old Camry with a JDM motor swap and a single high-flow cat can pass (everything but visual), your stock 4Runner will pass...

To be more specific, with a manual transmission, the tech can game the rollers a bit more by choosing gears - along with how the engine is loaded before/during the test. Most often it is done to get better numbers, but unscrupulous techs can go the other way (with the hope to get you to come back to get tested again).

-Charlie

How did they fail you on the "visual" part ? Can they guy just say, "I don't like how your car looks, and then fail you ? Seems like gov't B.S. to me.

I don't remember the details as it was years ago, but phattyduck nailed it, the smog dude was trying to fail me so I would use his shop for repairs. Called him out on his b's and he did the test properly.

Definitely fix the high idle issue, then just take it in to get tested. Sometimes the numbers will help you to see where to look next for repairs, in case of failure.

They check what emissions controls your car should have, and make sure all of those pieces are in place. I'm not sure how they check to see if a catalytic converter is acceptable or not, but I imagine it's something like a required label that if missing means it's not acceptable.