Hey guys,

I hate to beat a dead horse here as I've seen the countless threads about the dreaded P0770 CEL code but I just can't help myself.

Original Problems:
I started noticing about a month or so ago that it was taking my 4runner higher and higher RPMs to engage lock up when merging onto the freeway. I'm talking 4-5k RPMs before it finally hit lock up/overdrive. It was LOUD. Eventually it finally threw the P0770 code. While I was doing all my research online about the code I started noticing other symptoms. It would occasionally start slipping from engaging into 1st and struggled considerably more than usual going up hills.

The Repair:
I finally had the courage (after enough online research) to approach the repair. I replaced Solenoid E/Solenoid SL and replaced the transmission filter while I was at it. I didn't see any metal shavings in my pan (or if there were they weren't obvious to me). I put everything back together and the code miraculously cleared itself! I was ecstatic. I did a few drain & fills to cycle the old fluid out over a period of a few weeks that it was long overdue for and have been driving it ever since.

Post-Repair:
Now my 4Runner is doing a LOT better but it's still not perfect. I can tell something just still isn't right. And the P0770 code returning the other day cemented my fears. It no longer slips from going into first, it doesn't struggle as much going up hills, and shifts are MUCH smoother and it is able to engage lock up/OD at a more reasonable RPM band typically around 3-3.5k now.

My 2 big problems that I'm left with are:
1) Acceleration in general is still sluggish compared to what it used to be
2) Lock-up remains ON in the lock-up OFF range (which is obviously is what is triggering the code to return)

I've been testing the 2nd issue on my drives to and from work lately. Before this whole thing started I could slam on the accelerator and the car would, appropriately, downshift as a means to accelerate more effectively. Now it doesn't do that at all. On the freeway I could slam on the accelerator to change lanes and pass someone but now it just stays in lock-up/OD and gradually accelerates which is obviously a struggle and not very efficient/effective in OD.

I tried disconnecting the battery for 10 minutes to see if resetting the ECM would change anything and it hasn't. I might try pulling the EFI fuse for the hell of it.

I've read the references to the FSM and how my other troubleshooting avenues lie in the valve body being blocked up or stuck or the torque converter needing replacement. I've also read the recommendations that you may as well swap in a used or new tranny at that point.

I don't have the current financial means to swap in a used or new tranny so if this is just how I'll have to drive it until I can afford that, so be it. I'm just posting this a hail mary if there's something easy I could try on my own that I'm missing.

I keep a document with all the repairs I've done myself and can reference that if need be. Thanks in advance.

P.S. Occasionally I'm hearing a "popping sound" when accelerating on the passenger side from what sounds like on the other side of the glovebox/through the firewall. I thought it was just loose rocks clearing themselves from my tires but then I didn't see anything trailing my car each time it happened...maybe unrelated but worth mentioning I suppose if it helps

Hey from what it sounds like from what you described, it seems as if you are experiencing symptoms of a failing torque converter. If you hear popping sounds coming from the front bell housing, with lagging acceleration and since replacing all solenoids the torque converter is still having trouble dis engaging lockout.

New to the forms this is just my 2cents. I’m currently in the process of diagnosing my same cell P0770.

When I had the P0770 the CEL came on and another code came up on the scanner...the code for O² Bank 1 downstream. After I replaced that of course P0770 came up but not the oxygen sensor.
I got together with John (the guy that sold it to me) and found out that he had replaced the first gear solenoid. The CEL came on again so John put in an O ring kit, but that didn't SEEM to work because the lights came on. We came to the conclusion that the original problem was the O rings, and not the solenoid.
NOW: There are 2 kinds of solenoids - one made in Japan and the other is not. The ECM couldn't communicate with the replacement solenoid even though the O rings were replaced. John put the original solenoid in, but I now have an EVAP code that I have to take care of, which will be later than sooner.