Toyota FJ Cruiser Forum banner
  • Hey everyone! Enter your ride HERE to be a part of this month's Ride of the Month Challenge!

41 - 58 of 58 Posts

·
Registered
Joined
·
837 Posts
BOW - You stated that you "changed the sensors".

You changed all four sensors ( 2 air-fuel and 2 oxygen), or just the downstream oxygen sensors?

And you did thoroughly clean the mass airflow sensor in the intake air duct upstream of the throttle body?
I only changed the downstream O2 sensors. I also cleaned the MAF 2x because the first time I didn't clean down the tube where the actual sensor is, I just cleaned that glass orb on the outside. I also ran cataclean through last weekend. I never reset the codes after the cataclean because on the bottle it said the lights should go off if that was the issue so I'm waiting for that. I'm about 1/4 of the way through the tank after refilling from the cataclean application. I have stock DENSO spark plugs on order that should be here this week sometime. I was also thinking about cleaning the throttle body.
 

·
Registered
Joined
·
1,266 Posts
I've cleared the codes a few times. They come back once the engine is warmed up from completely cold.
Maybe the sensors are dirty from unburned fuel.
Give her some full throttle acceleration making sure the exhaust is hot.
 

·
Premium Member
Joined
·
169 Posts
To dredge up an old issue.
1. I Checked for leaks on exhaust and intake, cleaned MAF.
2. Reset codes.
3. Tried Cat Clean.
4. Replaced O2 sensors, but not A/F sensors.

1 to 3 and the lights come back after 10 miles.
4 and lights came back after +50 miles, but already inspected , so renewed and worry till next year.

I'm going to check the gas cap and replace spark plugs (they are getting close to due)

I don't know if anyone else has replaced cats to where it does not come back.

4 lights of death are also due to:
Speed sensors to misfiring, loose gas cap, bad brake light switch.
http://www.fjcruiserforums.com/forums/engine-performance/96371-4-lights-death-abs-vsc-traction-contol-skid-control-questions.html
If there is no code and the lights come on while using the brakes, then your brake switch contacts are dirty.
 

·
Registered
Joined
·
16 Posts
Discussion Starter · #44 ·
Dredging up a super old thread...

My P0420 and P0430 issues returned a year or so later so I changed both A/F sensors and the MAF sensor. The dammed CEl would come on every morning and afternoon like clockwork after the sensors were replaced.

Ended up being a simple fix. I disconnected the battery for a while and let everything reset. The CEL has not been on since. Now at 150K.
 

·
Premium Member
Joined
·
169 Posts
I've been playing with new toy and fixing the daughters car getting it ready for when she starts driving.

I've still got the lights, so in the next couple of weeks it's next on the list. I've still got trans shudder too. Talking with a transmission guy it could be the trans cooler is too close to the cats and with the skid plates retaining too much heat and breaking down the fluid. He did an aftermarket cooler routed forwards for a taco with the same issue. Never had another problem.

Think I solve the issues with the FJ and wait and see. Maybe sell it and get a new Supra or Bronco when they come out. All our kids are finally driving.
 

·
Premium Member
Joined
·
169 Posts
I believe it's the AF sensor on passenger side that I still need to replace. My inspection is up in Aug so I'll do it before then. If you don't have inspection to get tag then don't worry about it.
 

·
Registered
Joined
·
2 Posts
My alternator went out and i drained the battery as i was driving into autozone. Got a new alternator and battery(as it was 6 years old), then the 4 death lights came on within 12 hours and autozone said p420 code. Toyota said i need a new catalytic converter and wants $3,000.00. I found it ironic that other people had the same thing happen. Did everyone end up getting a new converter? I tried cataclean. I’m a female with not a lot of knowledge about autos and not sure who to have fix it. I bought it in ‘07 new, been the owner the whole time. Kept up with service at the dealer. It has 157,000 miles. this is my first problem with it. Thank you!!!
 

·
Premium Member
Joined
·
169 Posts
Most of us check fuses. Look for air leak on intake. Catclean. Replace cat sensors. if none of that works then the cat. I've still got to replace another sensor and see if that works. Just been dragging it out. Wife is thinking she might like a new Bronco and let me sell the FJ.
 

·
Registered
Joined
·
22 Posts
My 2007 is at 132k miles and had to replace the alternator. I too drove it until the battery dies and had to jump start to get it to the shop. Before there alternator failed, I'd replaced the spark plugs and MAF (causing CEL) within the last 2000 miles. I am now getting the 'four lights of death'.

I disconnected the battery and put pressure on the brake pedal which cleared the dash lights. All four lights lit up again after ~40 miles. Below are the only two failed tests from the Blue Driver 'Mode 6 Report'. I have more report uploaded on this thread. (https://www.fjcruiserforums.com/forums/engine-performance/731322-p0420-p0430-can-i-get-witness.html)

Should I start replacing O2/AF sensors or start looking for Catalytic Converters?

Thanks!

· Catalyst Monitor Bank 1, Manufacturer Defined Test ID range — This parameter
is an identifier for the test performed within the On-Board Diagnostic Monitor., ✗,
Status: Test Fail MID: 21 TID: A9 MIN: 0.038735 VAL: 0.023485 MAX 9.994000

· Catalyst Monitor Bank 2, Manufacturer Defined Test ID range — This parameter
is an identifier for the test performed within the On-Board Diagnostic Monitor., ✗,
Status: Test Fail MID: 22 TID: A9 MIN: 0.038735 VAL: 0.003050 MAX 9.994000
 

·
Premium Member
Joined
·
169 Posts
I finally replaced the other sensor up on the header. The four lights of the apocalypse came back after 20 miles. I cleared them twice and they come back after about 10 to 14 miles. Replacing the sensors don't seem to solve the problem. Someone else here even replaced the cat and the lights came back. I think it might be more of an electrical issue the the CPU. There are various threads on here about the cats and sensors. The alternate one tends to be a fatal one. Some get them and they are solvable.

I've had mine since new in 07. 129K miles. I've gone through the early front and rear diff flushes to avoid the wear issues. The transmission shutters due to heat breaking down the fluid since the second cats are right next to the tranny and there is no real cooler for it. Also, if you run larger than 32 inch diameter tires it drops the RPMs below 15K and in OD that's freaks out the trans valve body which promotes shutter. I've also dealt with steering wheel shake from mud terrain tires (no front stabilizer option to add). The window seal trim degrading and falling apart. Hood struts have gone bad. Alternator and now these codes have been an issue for over 3 years. I've grown disappointed with the it, but the wife says "It's such a great vehicle" but she don't fix, maintain or service it. I'm beginning to hate it.
 

·
Registered
Joined
·
22 Posts
Thanks X-Wing.

I've ordered replacement sensors (all 4) but now I am hesitant to replace them. Especially since none of them are failing tests. As for the catalytic converters which are both failing, I'd think that replacing them would resolve the issue but would be expensive. And as you mentioned, didn't resolve the issue for at least one person. There are a lot of conditions/indications that the converters could actually be bad.

'IF' I were to replace the converters, does anyone know of an aftermarket 'upgrade'? Might as well get 'better' performance if I have to spend the money.

Has anyone replaced the ECU? Thoughts on that?
 

·
Banned
Joined
·
21 Posts
Just as an FYI, the ECU's are just plain to sensitive for the Cat efficiency fail codes P0420 and P0430. You can have as little as a 5% restriction with the cat working fine and throw these codes.

I am also plagued with these cat codes in a Sienna and just sick and tired of this problem.

The other issue is the scam sucking Toyota blood sucking leaches disabling the VSC and traction control. That pisses me off the most since it's a safety device that Toyota is using as bait to scam you back to them to sink thousands of dollars in repairs. Everyone needs to place a safety complaint with the NHTSA and ask that a recall is done. Most states don't require emissions testing so all of us shouldn't be held hostage with the 4 lights glaring in our face and driving an unsafe vehicle for greed. Since the consumer protection is such a joke my only alternative is to try the O2 simulator method. Has anyone had any luck with the URD simulators?
 

·
Registered
Joined
·
1 Posts
So did anyone ever find a definite solution. I had the same issue and I've changed my downstream O2 sensors. Cleared the codes and they come back after a few miles. I have no issues with the vehicle running/loss of power/limited speed. FJ runs normal as far as I can tell.
 

·
Registered
Joined
·
704 Posts
I am curious myself about this (not the alternator part though). I just replaced the front header cats due to the lights and Toyota said they were both "BAD", showing me a graph and value print out. Replaced the headers and replaced one O2 sensor. Drove for a week, all codes came back.


So did anyone ever find a definite solution. I had the same issue and I've changed my downstream O2 sensors. Cleared the codes and they come back after a few miles. I have no issues with the vehicle running/loss of power/limited speed. FJ runs normal as far as I can tell.
 

·
Premium Member
Joined
·
2,160 Posts
Just as an FYI, the ECU's are just plain to sensitive for the Cat efficiency fail codes P0420 and P0430. You can have as little as a 5% restriction with the cat working fine and throw these codes.

I am also plagued with these cat codes in a Sienna and just sick and tired of this problem.

The other issue is the scam sucking Toyota blood sucking leaches disabling the VSC and traction control. That pisses me off the most since it's a safety device that Toyota is using as bait to scam you back to them to sink thousands of dollars in repairs. Everyone needs to place a safety complaint with the NHTSA and ask that a recall is done. Most states don't require emissions testing so all of us shouldn't be held hostage with the 4 lights glaring in our face and driving an unsafe vehicle for greed. Since the consumer protection is such a joke my only alternative is to try the O2 simulator method. Has anyone had any luck with the URD simulators?


I just received the O2 simulator today from Steve/URD and will install it on my day off and let you guys know how it went.



Sent from my iPhone using Tapatalk
 
  • Like
Reactions: WebSnyper
41 - 58 of 58 Posts
Top