Help Passing Emissions on a Toyota Van?

[s2cmpugh]

oh yeah AZ is really lenient, all they do is check for CELs and to see if the readiness sensors are ready and reading as they should. They'd even pass the car if only 1 of the readiness sensors is reading properly. In this case, they check the Catalyst and the EGR

I'd say go for it then! If you're planning on replacing the sensors anyway it should maybe another 2-3 mins. to the job tops. Also, after you do a few drive cycles, check to see if there are any "pending codes" before you take it in, but do NOT clear out the system. It will reset the readiness sensors and you have to start all over again.

Let us know how it works!

By the way, this is why I hate OBDII. For example, if normal cat. efficiency range is 90-100% and it drops to 89.99999999999% you have a CEL and fail emissions....so damn stupid and costs people way too much money.

[wed3k]

It shouldn't. That last A/F sensor is simply used to check for cat. effeciency and does not effect the drivability of the car. The first A/F sensor has the primary job of determining air and fuel ratios.

This trick might work to make the CEL stay off, but all the emissions station has to do is stuck a probe up the exhaust and they can tell if something is wrong. Keep that in mind.

the 2nd sensor is usually a regular o2 sensor and not an a/f sensor. the last o2 basically just checks for mv. low mv means a lean mixture and an excess in oxygen which would generally mean a cat is no longer efficient.

if you don't warm the motor up properly, the cat won't be efficient when the rest of the motor gets to operating temperature.

for the most part, an "inefficient" cat still passes even california emissions. im sure it will be fine for az emissions

[Losiracer2]

Well the damn lights came back again. I even replaced all 6 spark plugs and it went away for about a month, then came back.

So I went out and bought those non-foulers, BUT there's a problem. The rear O2 sensor isn't threaded into the exhaust pipe, but BOLTED into it using 2 12mm nuts threading onto studs. When removing the nuts, both kinda snapped the studs off so I had to unfortunately remove the mid pipe off the car.

The studs snapped off pretty low in the flange so there's quite a bit of threads left so I bought some new M8-1.25 bolts to put back in.

Another problem is the O2 sensor hole isn't threaded, since it bolts in so the opening would have to be tapped for a M18-1.25 thread.

So, what I plan on doing is getting longer bolts (1.5" ones) and using those to bolt the O2 sensor onto the non fouler that's threaded into the mid-pipe...think it'll work?

I'm going to take it to a machine shop to tap the threads since I can't find any M18-1.25 taps locally. If I did they'd probably be pretty damn expensive.

IDK, I've tried everything. O2 sensors, Sparkplugs, so I really hope this works.

[wed3k]

wow ive never seen that setup before. my toyota pickup/tacoma has a regular o2 in the back.

[Losiracer2]

wow ive never seen that setup before. my toyota pickup/tacoma has a regular o2 in the back.

well I managed to do it. Luckily I found an Ace Hardware that carried more industrial sized taps, and found an 18-1.5 tap for 17 bucks. I went to sears and got a tap handle for 18 bucks. Tapped the flange in the exhaust and then returned both things later on and got my money back lol.

Minivan works great, no leaks even though the O2 is just sitting inside the non-fouler tightened onto the exhaust. CEL's went away...for now...since I unplugged the battery, I'm crossing my fingers they'll be gone for good now.

[s2cmpugh]

Sorry the P0420 came back man. If the foulers don't work that really only leaves one option left, cat. replacement.

However, I've been doing some research on that code and found a guy named Scotty Killmer who has apprently been a mechanic for 40 years or so. Here is a youtube video of his showing two ways of how to clean it out. Also, if you remove it and notice the honeycomb starting to fall apart, you need to find out why that happened (leaky injector, running too lean, etc.) Obviously, up to you if you want to follow his ideas, but it certainly can't hurt anything:

[wed3k]

if you have a data scanner check if the catalyst monitor has completed.

the code is also time based. if you don't allow for a proper warmup then the catalyst will be inefficient especially after the motor has been warmed up.

i see the p0420 often and ask if the customer warms up the vehicle and they look at me all wierd. all it takes is about a minute or so.