greetings, friends.

i'm back.

i have a 99 SC300 now. in VERY NICE SHAPE, and got it for $3000 from a local rich guy. now i have my RX7, and the best mod you can buy for an RX7, a 90s Lexus.




i just got the dreaded P1121 CEL, and after doing a little research, i figured out how to fix it without spending $300 on a new A.P.P.S.

for those of you who aren't familiar with this, this is the NEWER (read: annoying) setup that is only on the 98-2000 SC300s, 01-05 IS300s, and 98-02 GS300s:



these stock ECUs read the pedal position up at the back of the throttle body (as opposed to actually down on the pedal like other modern cars... it was an easy transition for toyota i guess?), check the value against the TPS that is located on the front of the throttle body to make sure the two match (a failsafe, i guess), and control the electronic throttle motor at its discretion.

anyway, my car was throwing a CEL for P1121, but it would only come on after the engine warmed up and the engine sat and heatsoaked for a few minutes and heated up a little more... weird. so i found a guy over in the GS section who re-soldered the 4 solder connections inside the sensor, and WALLAH, it's perfectly fixed. so i did it:




here's mine after a little mouse chewed it open for me (just kidding) and re-soldered. i did this by heating up each little solder connection, sucking the solder off with my solder remover, and re-soldering it:






ALL FIXED. it's been perfect. i hope this helps.

 

Nice. Is this SC going manual as well?

 

Welcome back, nice cars....only 3 grand? Good deal

 

enforcer. no 5spd swap for this one.

 

If you need that part , I have a spare tb I can send you if it doesn't fix your problem.

Welcome back! Where have you been ?

I like that rx7.

 

Cartmill, why is it that all previous SC owners always come back? It might be a year or a week, but they always seem to find their way back. I hate that you went a stray and went with some Infinity rides, but I am glad you are back. I just knew it.....

I need you to come down and fix all my wiring issues on my SC. JK. .Still runs good.

 

I had this problem years ago and ended up buying a new APPS. I wish I knew it was such an easy fix. Thanks for the info.

 

marky mark, is that you???? long time no see

 

This thread will be vastly helpful when people are head on with this problem in the future. This happened on my 98 about a month ago.

 

LOL two months on the GS Side and still couldn't figure this out LOL Thanks a bunch! I hope this applies for the 1uz throttle bodies

 

Did you cover that hole with anything? I am having the same issue and think I have seen the other post you are referencing. I think that guy said he covered his with silicone, but if I ever needed back in there it seems like that would be a mess. Curious what you did.

 

yes it does apply to the later 1UZ for the 98-00s (i think), but the APPS is actually different. same issue, but a slightly different sensor (different OE part #).

i did not. i just left it open. it should be filled with epoxy or RTV, but i just left mine open. if it messes up again i'll just buy a new sensor.