P0420 + 4-wheeling... What to do?

[eric_rosenwald]

I recently bought a used 2004 4Runner. It's an unusually excellent condition. I made sure to bring it to my regular mechanic to check it and smog it before I bought it. He said it looked great, and it passed the smog check.

The previous owners said that it had never been off Road. The owner before that didn't either. It's no surprise, it doesn't look like it had ever been on rough roads. It drives like a new car. It just has that feel when you're behind the wheel.

So I just took it out to Death Valley, bringing 6 gallons of gas. I have a RotoPax 2 gallon and just normal store-bought 6-gallon tank filled to 4-gallons. I haven't used the store bought one in a while. It sloshed around a lot in the back of the vehicle. I know it's not safe to roll with gas inside like that, but I took a lot of precautions, wrapped it in a bunch of contractor bags and refueled, emptying the 6-gallon tank at the end of the day. The RotoPax was brand new, and spent 2-days on my roof.

It handled rough roads perfectly. I went up Hunter Mountain Road, and it performed well. After about 60 miles of driving on death Valley backroads, I got a check engine light. I stopped immediately, and checked out everything (next time I'll bring a code reader). The engine looked fine. Fluids were okay, no leaks whatsoever, started and idled just fine.

I encountered dust that was finer than any dust of ever I've ever come across. It was like volcanic dust. The car is completely covered, it sticks as if it were static electric. The tires look silver. My hope is that this is a factor, making this whole thing a minor issue.

I drove to Lonepine to get it checked. I just got a P0420. From what I understand, it's an O2 sensor dealing with the catalytic converter. "Catalyst Efficiency below threshold (bank 1)"

Considering I took it four wheeling for the first time ever, and put it in the worst dust I've ever seen in my life, I'm hoping this is somehow a culprit. Also, using gas that had been in considerable heat, and the gas can potentially had some impurities. I may have also got a little bit of dust in the tank when I was refueling out there. I checked the fuel cap, it's on but there's some dust in that compartment.

The guy at Napa (the one who let me borrow the reader) told me to just clear the code, drive it around and see if it comes back on. I'm about to do all of that after I post this.

Any suggestions? Am I safe to continue my trip?

Sorry for any typos… I had to dictate this entire post on my phone.

 

[shootmymime]

Any suggestions? Am I safe to continue my trip?

Sorry for any typos… I had to dictate this entire post on my phone.

clear it, (this can also be dont by pulling the EFI fuse under the hood for 1 min) drive it, see if it comes back (may, may not.) if it does replace the sensor. you wont have any problems right now except lower fuel millage, then the motor might start running rough.

how far are you away from home? im sure you should be fine.

anyways congrats on the new 4Runner!

 

[snivilous]

Don't worry about it until you have time to mess with it. It's not a critical component by any stretch.

 

[Supermoney]

You have a 2004, wrong section?

Anyway, I had the same code on my 3.4 and somehow a new (used) MAF fixed it. I was cleaning my old one regularly to get the engine light off but it kept coming back -- usually when going up steep hills and really making the engine work.

I found a used MAF off a 08~ Toyota, popped it in and no check engine light in 1000+ miles even up steep hills.

As far as driving it with that code, its not a problem at all.

 

[morbidsanity]

i had the same thing a few weeks ago....ran some sea foam in the gass and did a sea foam smoke out and cleared the code....running fine for me cleared the code no problems....its just a dirty cat converter...

 

[eric_rosenwald]

so far, so good...

clear it, (this can also be dont by pulling the EFI fuse under the hood for 1 min) drive it, see if it comes back (may, may not.) if it does replace the sensor. you wont have any problems right now except lower fuel millage, then the motor might start running rough.

how far are you away from home? im sure you should be fine.

anyways congrats on the new 4Runner!

(someone else here thought it was a 2004... It is a 2000.)

I cleared the code and drove it 50 miles... half of that uphill. I floored it several times, took it up to 95... It sounded great. The engine was running smooth, even after stressing the hell out of it. No warning light. Right before, I thoroughly wiped up the gas cap area with a damp cloth. I cleaned the cap, the rubber around it, the metal post that the door clicks into.

I have no real evidence to support this... But I just have this feeling that it had something to do with the stress I put it under a few days ago. I was going uphill on 4x4 roads from about 2,000 ft to 7,500ft altitude into the mountains... Maybe the exhaust got a little dirty from those added stresses? Sounds like the MAF could have been dirty?

Either way, I feel confident to continue on the trip.

I'm about 150 miles from home.

 

[eric_rosenwald]

i had the same thing a few weeks ago....ran some sea foam in the gass and did a sea foam smoke out and cleared the code....running fine for me cleared the code no problems....its just a dirty cat converter...

The previous owner said he only put the highest octane gas in it... I just put 87 in it. I'll refuel it before I continue. Should I get some fuel injector cleaner when I gas up?

 

[morbidsanity]

The previous owner said he only put the highest octane gas in it... I just put 87 in it. I'll refuel it before I continue. Should I get some fuel injector cleaner when I gas up?

ok first off high octane gas is worthless on a 4runner unless your running a hi performance setup ie larger cylinders/supercharger....ive heard its worse to put it in....stick with 87... you really dont need anything more or less.... try sea foam i swear by it....most feul cleaners are a waste of money, sea foam has been around forever, put half can in gas other half through the intake like in the video....just be gentle! not to much at once! good luck!
https://www.youtube.com/watch?v=RshzQ-YH6Jg

 

[jgue467]

(someone else here thought it was a 2004... It is a 2000.)

So i'm guessing your VSC lights went on also? Per the beloved FSM for 96-02s p0420's are caused by one or more of these: 1) Gas leakage on exhaust system, 2)
A/F sensor (bank 1 sensor 1), 3)
Heated oxygen sensor (bank 1 sensor 2) or finally the
Three-way catalytic converter. Check 'em in that order as they get more expensive as you work your way down. Luck! :banana:

 

[lude and rude]

i have had this code for approx 1 year (only owned the runner for that amount of time). i changed both O2 sensors, ratted out muffler and exhaust gasket with no luck. i can clear the code and 2 to 3 weeks later it comes back. its one of the those codes that doesnt mean awhole lot if your runner is still running decent. its more of an annoyance. if you do in fact want to replace O2 sensors only go with denso. find them on here: Oxygen / AFR Sensors - Underdog Racing Development first. i would have an exhaust shop check for leaks in the system also or even before replacing parts. good luck to you. many 4runners will have this code and who knows the original owner could have had it pop up a time or two.

 

[BrianSD_42]

Just clear the code and keep driving.

 

[TheDurk]

Just clear the code and keep driving.

This. There is no affect on performance or MPG from a stand-alone P0420. It is an over-sensitive indicator that you MIGHT be polluting the atmosphere more than the optimally functioning vehicle. Nothing to affect a trip.

 

[jgue467]

No - no performance lost but don't you get the damn VSC/TRAC lights to come on? I know no one on here likes VSC/TRAC, except me -have saved my arse many times on dirt roads while hauling it-woohoo! Unfortunetly in many Texas counties you can't have a CEL if you want a current inspection. Who needs a stink'n 'spection sticker or a badge, huh? We can have guns all we want but no CEL - go figure!! haha! :banana:

 

[eric_rosenwald]

I had no other lights go on (What's VSA/TRAC?).

Well I ended up clearing it, and drove an entire day without a problem. I'm wondering if there were sediments in the tank that got shaken up after some serious backroad driving and shaking? It had only ever been on streets before.

Having said that, I have a completely different issue now... After driving a couple of hundred miles, I start hearing a faint squeaking sound... It sounds like a belt to me, but after feeling them and checking them as best as I could, I don't see a problem.