Federal 1997 SR5 failing smog in California - Need some advise

Hi All,

New to the forum but long time browser and life long Toyota guy.

A couple of years ago i purchased a federal emissions 3rd gen 4 runner. It was registered and smog-passed in California before purchasing.

Fast forward 2 years it is failing smog due to high NOx readings. It's failed a couple of times, but probably mostly due to my ignorance. Car was not properly warm, only drove a few miles before having it checked (Twice!)

I had the car checked for for any vacuum leaks and MAF and it seemed good (No check engine lights as well). After some research, a lot of people suggested getting a magnaflow CAT to pass surefy.

Long story short, I messed up and purchased a CA cat for this Fed emissions 4runner. I made an assumption since the car had been registered in CA that I should purchase a CA Cat.... After driving around 60 miles or so I went to have it tested. The Smog station failed it due to the illegal CAT and is suggesting i see a state referee or figure out a Proper Cat.

Im tempted to go to another station and not mention the New Cat. But i believe they do a visual test and may fail it anyway.

Should I bother seeing a state ref who may fail the car anyway?

I would love some advise. Thanks!

 

Well, you could have saved the money spent on the CAT.

Before a smog check, always drive the vehicle on the freeway for five to ten miles to get everything good and HOT! Even better if you can put a load on it by going up some hills before getting the smog check. I wouldn't replace a CAT until the smog man tells you to based on the readings seen during the check.

 

Welcome

 

Do you have OBD2? Better OBD2 readers have not only CEL readouts but can also confirn your vehicle is ready for smog testing.
The information logging in the vehicle computer is complex. Speed & distance are saved plus other complex readings.
In general-you need a mix of around town and highway/freeway miles. Some believe putting premium gas in tank weeks before test. Tank should be above 1/4 but not above 3/4 . These are just a few items I remember.
You need advice on correct CAT. So the State ref might help.
Also study the CA smog web site.

 

Listen to this guy.

Last time a friend had some trouble passing smog in his older Tacoma. I hooked it up to my cargo trailer that weighed about 3k empty that I usually use for my F250. Drove it from east bay to Modesto and back over the altamont pass twice. passed it the next try. A lot of times with all unloaded miles truck cats get very clogged and some italian tune up with load helps push it over the legal line.

 

Altamont Pass has been my friend when it comes to getting an older vehicle to pass smog. That and consuming a tankful of Chevron Supreme a week before the smog test. Drove up and down the Altamont four times before taking the car to the smog man and it passed - this was a beater 2001 Honda Accord.

 

High NOx is indicating lean mixture, high combustion temperature. Might want to look for vacuum or intake leaks, or a faulty feedback leaning the mixture. A vehicle that is not fully warmed or running in open loop should be running slightly rich (higher HC, CO). A properly working cat up to operating temperature would clean up the excess HC

like stated, you need to ensure the vehicle is prepared to test, especially on an older vehicle. Back in the day, before most states abandoned exhaust analysis for OBDII systems checks, you would dump a couple bottles of “dry gas” (isopropyl alcohol) in they tank and give it an Italian tuneup before hitting the testing station.