Smog Testing Readiness

Our 2000 Tacoma is an SR5, 2wd, AT, 5VZ-FE. Went to smog it a few weeks ago and the test guy told me it wasn’t ready. I came home and put my OBD reader on it and it said the Catalyst wasn’t completed and I had a pending P0420.

I did the shop vac on the muffler trick and found multiple exhaust leaks at two of the exhaust gaskets. I red RTV’d both those unions and verified the leaks were gone. Drove around more and got the full code this time, P0420. Cleared the code and replaced both the upstream and downstream O2 sensors.

Ever since I replaced those two sensors, I have driven it and driven it and driven it. The code has never some back and nothing is pending either. So it seems like I fixed the problem, but STILL no smog readiness. I cannot get the Catalyst to complete its test. And ever since that last time I cleared the codes, I also now can’t complete the Evap System test.

I am following the directions in the factory TSB EG003-02 concerning “Readiness Monitor Drive Patterns.” I don’t understand why they both won’t run but I’m also no longer getting any codes. The truck runs great but now my registration is expired. Ideas?

 

I don't know, but I'm surprised that RTV red will seal up exhaust leaks at the unions without disassembly. I have minor leaks at 2 flange gaskets and one exhaust manifold, testing the same way you did.

Edit: Actually when I need to do a drive cycle to check codes I don't do anything special, I just hop on the freeway for a good while, and between that and everything else it gets done.

 

I would have left California. My uncle lives in Monterey and has to register his 1977 VW Westfalia at his brother's house in Texas because the bus won't pass smog, and there is no loophole for antique vehicles in California; ALL VEHICLES NEWER THAN 1975 MUST PASS SMOG IN THE MOST POPULOUS COUNTIES, AND IT'S STUPID!

 

Have you verified your coolant temp is getting high enough?

The monitor will not run unless: MIL is OFF. ECT (Coolant Temp) is 176F (80C) or greater. IAT (Intake Air) is 14F (–10C) or greater.

 

Drive that Bish up the 2 and into Palmdale( if it’s open yet)

 

I’ve done all this. Yes my coolant temp is high enough. I’ve verified coolant temp at start up and at operating temperature. I’ve done the cold soak. I’ve driven from Burbank to Magic Mountain and back. Twice. Plus miles and miles of in town driving. Hoping the fuzz doesn’t pull me over with my expired plates.

 

Some of those readiness monitors are weird about the speed they need to complete. Don't remember where I read it, but I think the catalyst monitor needs something like 55mph for 20 minutes or something surprisingly long (don't quote me on those numbers).

 

I’ve driven 340 miles since the beginning of this problem. Granted, I did have to clear the p0420 one last time before I replaced the sensors. But I’ve put at least 100 miles on it since then.

 

I’m using the Toyota TSB as my guide. I have the exact requirements.

 

This.

 

Being California emissions yours would be the AF sensor type but the drive pattern looks pretty similar.

EVAP and catylyst monitors seem to be the hardest to get to run on older vehicles, we don't have to deal with readiness monitors being complete here other than using them to verify a repair so I don't have alot of experience in tricks to get them to complete.

Are all the other monitors completed like O2 sensor and O2 sensor heater?

 

For a stubborn cat monitor I have had some sucess doing the following. From a cold start let it idle for a few seconds then rev her to 2500 rpm and hold it there for 3 minutes then check your monitor. I know it doesnt make ANY sense but like I have said it has worked for me a few times.

Found the video

https://www.youtube.com/watch?v=BuZYAy_xi0E

 

Yes, they all complete very quickly.

 

I will try that today. Thanks.

 

Hey, this partially worked! I let the engine warm up to 176, then held a steady 3000rpm for 3 minutes and I completed the Evap System test. So I’m partially there. Still need to complete the catalyst, but now I can just focus on that.

 

The cat test is a bitch... 55 mph for 10 minutes, yeah, right. When I have to do this it is 10 at night to avoid the traffic. The other thing i can tell you is that if you have your scanner hooked up and are driving and monitoring for cat completion, it wont complete while you are watching, why, have no idea just how it is at least for me.

 

I’ve wondered about that exact thing. So I stopped doing that as well. Now I just drive it and check it when I get back home. Drove 40 minutes, roundtrip, on the freeway last night, and didn’t look at it until I got back home. Still incomplete.

 

I looked for an answer but have found it yet... I know that certain years of vehicles in CA can be smogged with one incomplete monitor, does that include the CAT monitor, like I said cant find a definitive answer.

 

You can have one CEL for the other checks. BUT it cannot be the cat monitor.

 

Yeah, when I went to smog it a month ago, and he said it wasn’t ready, it was only the catalyst that was incomplete. I checked it when I got home that day. I also had a pending P0420, but he didn’t mention that. So, pretty sure I have to keep trying.