My First Time Experiencing "Limp Mode" and Have Problems & Questions...

[T4R2014]

Now we got what was needed. If you can't see any damage to the TPS wiring I'd go straight to throttle body replacement. Cleaning the throttle body won't fix that code. Get yourself a nice coolant bleeding funnel. If you are doing this, I recommend you add new throttle body coolant hoses and clamps to your OEM parts order. They're all starting to get baked after 20 years under there. Only 50 extra bucks about, if I recall. That was pre-tariff though.

 

[eddielasvegas]

Again, thanks for everyone's comments. Very helpful.

I'll update the thread once I figure this out.


Eddie

 

[96RedRunner]

I'll update the thread once I figure this out.
Eddie

DTC 1120 same here I opted to go new TB. Left me with a new in the box
Aisan 4 pin Throttle Position Sensor Part Number: W0133-2744128 Partsgeek.

Edit: Put it to use, send me an address.

 

[Jidaran]

Piggybacking on this thread since I'm having the same exact problem.

2002 with 290k. Died suddenly while driving on surface streets. P1125 and P1128. Cleared them and it started back up. Drove home a few miles without issue. Started up fine the next day and did a few laps around the block. Took the TB out to see if I could ID any issues. Other than some carbon build up and a cruddy PCV valve, looked fine. I haven't had any of the idle issues that are often related to a bad TPS.

Everything I'm reading suggests the fix is either the TPS or the entire TB. The 4 pin TPS is $50 shipped. TB is $450. If I was having consistent issues, I'd just replace the TPS and hope that fixed the problem. But the inability to replicate the issue has me a bit worried - if a new TPS isn't a fix, I might not know until it dies randomly a few days later. Not trying to spend $450 if I can avoid it though.

I really wish I had a backup TB on hand, it's been on my list of junkyard parts to pull since I got the 4Runner. But it seems that those things disappear from the engine before the truck even hits the yard....

 

[T4R2014]

I'd recommend just getting a new TB at this point. I'm beginning to notice the 96-00 throttle bodies getting stiffer to turn from age. Bearings just wearing out at this point, I'd imagine 01-02 isn't very far behind. I'm sure they can be replaced but with how much effort?

 

[Jidaran]

I'd recommend just getting a new TB at this point. I'm beginning to notice the 96-00 throttle bodies getting stiffer to turn from age. Bearings just wearing out at this point, I'd imagine 01-02 isn't very far behind. I'm sure they can be replaced but with how much effort?

I think that was the right call. Next time I took the 4Runner out, I got a fault about 5 minutes into the drive, cleared it, turned around, and got another right before the house. Went ahead and replaced it, no issues since.

 

[eddielasvegas]

Hello All,

My profound and profuse apologies for not updating this thread, but I flat our forgot about it until yesterday. I'm blaming old age.

The good news is the issue is resolved and it was the APPS (Accelerator Pedal Position Sensor). It's been exactly 3 months and no return of the limp mode. And my T4R is clearly more responsive now too, which ain't saying much for our beloved vehicles, but it's noticeable.

The bad news in all this is the APPS is not available as a standalone part, but must be purchased as part of the Throttle Body assembly. This assembly includes the TB, APPS and TPS. I also replaced the TB inlet and outlet too.

The parts were expensive (slight discount to retail) since I didn't have the luxury of time to order online, but at the end of the day my pocket book could handle it and I love my T4R so much that amortizing the cost over 10-20 years is like a gnat on an elephant's behind.

I did use a mobile mechanic, who came highly recommended, as I did not feel like dealing with towing since "limp mode" was almost a certainty given my regular mechanic is a hike.

Thanks again to all who replied to this thread and I'm happy to answer any questions.

Eddie