MAF O ring size

Do you guys know what size the O ring is for the MAF sensor on an 02 with the v6 is?
I'm chasing down the cause of my P0420 CEL. Today I replaced the gas cap with an OEM unit and while cleaning the MAF sensor I noticed the o ring has been pinched and is swollen.

Hoping I can get one today and see if these 2 items will fix it.

Thanks!

 

A P0420 is catalyst inefficiency. You're barking up the wrong tree, you've got a bad cat/cats, or a bad downstream O2 sensor... That's it

 

I wrote down 3 codes but I can't remember which one was the original before I Seafoamed the truck to see if the exhaust manifolds were leaking. I also had a P0171 and P0442 and obviously one or 2 of those were from unhooking the brake booster vacuum line to the intake manifold for the seafoam. I cleared the codes but I need to replace this O Ring before I drive it.

Anyone else know the O Ring size?

 

Do you still have the smushed ring, I replaced mine out of the generic harbor freight o ring kit just by matching them up side by side.

 

I do.
That's the kit I planned on getting. Just wanted to confirm it'd have the correct size before making the drive.
Thanks!

 

If you measure it I can check the kit for you to make sure, it's been like 6 years since I replaced it but I'm 90% sure I got it out of that kit

 

What he said and FWIW, introducing a cleaner thru the brake booster vac line on the V6 will reach only one cylinder. The other 5 will not see so much as a drop.

 

It looks to be about 1 1/4"

 

It wasn't so much to clean it as it was to see smoke coming from a crack if my manifold/s were cracked.

 

Cool, so change that to only one manifold.

 

But thicker but she's in there

 

T

Nice! What size is that?
Just picked up the kit

 

In the package named 215

 

Thanks! I went to a few places and couldn't find one that was of similar diameter and thickness. I used the 215 from the metric kit but I'm going to get an OEM replacement sometime so the MAF sits more flush than it is now.

Thanks for the help!

 

P0420 can also be triggered by exhaust leak upstream of 2nd O2 sensor. Check flanges for leaks.

 

Since you just recently "liked" my post, I revisited this thread and was hoping for an update. What exactly is the story, anyway? Re-reading this thread, it was a little confusing what the issue was that you were trying to solve. Did you solve your check engine light issue? Was there ever a P0420?

 

Sorry for the confusion. I've been extremely busy with work and many other things so I haven't been able to dedicate much time to the Tacoma.

CEL came on initially and I scanned the code which I believe was a P0420. I then reset it and it came back on a couple of weeks later. I then replaced the gas cap with an OEM replacement as well as Seafoamed the truck through the vacuum line that goes to the intake. The main reason for that was to make it easier to see exhaust leaks at the manifold. Because the truck was running while introducing seafoam a couple other codes popped up which was expected. I also cleaned the MAF sensor (which was dirty) and found the o-ring to be damaged.
Put it all back together, cleared the codes and the P0420 code returned.

Since it is now cold out I plan on putting a rag over the tail pipe and looking forward of the cat to see if it has an exhaust leak at the flanges.

 

Thanks for the update...I didn't mean to be pushy; it's useful to other members and lurkers alike to see how these issues get resolved.

In my experience, you need to look for an exhaust leak at the flanges between the two O2 sensors. Given that you are located in Illinois, it's plausible that something in the exhaust has rusted to the point of leaking. In the span of the last year, I had two flange joints fail. In the first case, the pipe actually separated while I was picking up my kid at preschool. It was a little embarrassing being "that guy" running an open exhaust in front of the other parents at pickup time. In the second case (months later), I got the CEL for P0420. I took the opportunity to replace the exhaust from the cat back to the tailpipe (muffler had a hole), but prior to this work, I noted that I could feel exhaust pulses from the last flange before the 2nd O2, and even saw condensation dripping from it as the exhaust was slowly warming up. I cleared the code and bolted everything up with a new gasket. I got lucky, because the code hasn't returned.

You may not get lucky and be able to locate and fix an exhaust leak thus solving the problem. In this case, if you're required to pass emissions, then your only other legal option is to replace the cat (or cats), which is expensive. Working on rusty exhaust is a real PITA, especially for the forward cat, which is more difficult to reach, especially with a grinder. Nuts/bolts are probably rusted to the point that there won't be anything there to put a socket on...PB Blaster need not apply.

 

@AmherstAndy

Your post didn't come off as pushy!

Illinois is awful for rust. I just got done fixing my other vehicle that had the flange break off before the cat so I understand the embarrassment!

Thanks for the tips on where to look. I'll get a solution of soap and water and start spraying the exhaust down before the cat. I briefly looked under the truck as it was warming up and didn't see any exhaust or drips from flanges or holes. I was trying to hear for exhaust leaks too but doubt I'd be able to hear it over the v6 on a cold start.


Family is now borrowing my truck so it will be a few days before I get a chance to check it out again.

 

Well I've had the truck back for a few weeks now.
I cleared the code and ran a couple bottles of Gumout Regane & Techron though the truck and the CEL hasn't returned even after a few hundred miles. Last time I cleared the code it came back after 15 miles. Hopefully it stays that way.

Cliff notes: 0420 CEL code, replaced air filter, cleaned dirty MAF sensor, Seafoamed truck, replaced gas cap w/ OEM, replaced damaged MAF oring, verified no exhaust leaks and ran Techron/Gumout. CEL hasn't returned.