NBKarnage

I'm yielding to the forum SOS! Which by the way, I've probably spent a day total reading around this site and it is an unbeatable resource and kudos to everyone for helping everyone.

Storytime, the girlfriend has a '99 RX300 that started to idle rough and lack power and spitting CEL's...so, having built 3 Toyota 4x4's from frame up, including 2 engine re-builds, I jump right in. Here's what's transpired and what's been done:

July 18th, 2013 - Codes pulled P0302, P0304, P0300 and P0120.

ACTION - changed all Ignition Coils and all spark plugs and tested resistance on all fuel injectors but #3 (bugger to get at as I didn't remove intake). Also cleaned MAF sensor and changed air filter. Codes cleared.

Car runs great for a day, lacks a bit of get up and go but no CEL.

July 20th...Codes P0120, P1133, P1153 pop up, car doesn't sputter but lacks power off the line. I order TPS (P0120 related). Try measuring TPS and continuity seems fine but I'm taking no chances with the Mrs. car. Codes cleared, ECU reset with fuse pull.
July 21st...TPS arrived, have not installed but additional codes popping up - P0110, P0100, P1154...cleared as I will be picking part up and replacing TPS shortly.
July 24th...TPS in hand finally but not installed yet and the damn P0306 comes up again with car sputtering and CEL flashing.

I will be testing both new and old TPS side by side this afternoon (bench test resistance), but I am in serious need of what else to look for if this doesn't solve my problems...I'm into this for some serious pocket change now and don't give up easily, plus my man card is on the line with the GF.

With how many problems and the diversity of them, I'm thinking:
- Ground wire problem?
- A/F Sensor problem?
- Plugged Cat? (What's the best way to check this anyways, rattle check?)

Any and all help hugely appreciated!

-Neal

code58

Where did P1154 come from? I don't even see an 1154 code in the list for OBDII codes. To begin with, I don't know what your problem is, but doubt SERIOUSLY that it could be ALL the codes you're getting. Whenever you get an outhouse full of codes like that, you can bet almost for certain that most of them are not valid! I would definitely check ALL grounds to make sure they are hooked up and making good solid ground. Too much tail chasing going on here. Take a deep breath and think it out. Chasing a TON of codes with parts will only empty your wallet and leave you broke with the problem staring you in the face.

Lexmex

Welcome to the Club.

The P0120 is not a common code and that one is the first one I would focus on for the time being. Fix that and then see if the P0100/P0110 comes up (that's next) and then see how many codes no longer pop up.

Keep us informed.

NBKarnage

Well, problem has been resolved...for now.

I pulled TPS and bench tested both new and old side by side. The new ones part # is the 3030 where as the 3040 came out. The new one was obviously smoother but also had slightly lower resistance readings. In comparing the voltage divider circuits between them, the new one was much more accurate...installed and car worked better right away, but still threw a CEL after awhile of driving.

I then went to the ECU, took all connectors off and cleaned. I measured all signals coming from the TPS to the connector when attached...as per page DI-39, 40 here:
http://bio.souz-96.com/Lexus/RX300_R...iagnostics.pdf

...all good and great help.

Only one code spewed shortly after 0306...took the 2 secs to swap it to #4 and reset/cleared code. It came back on but with 0304. Took an old known working ignitor coil and threw in. CAR HAS NEVER RUN BETTER. So it looks like I got a defective brand new coil from the store...fun. I do believe there was a slight grounding issue somewhere (ECU probably) but it is working great for last 3 days. Also, reset ECU with connectors detached for 1.5 hours.

Will keep posted if it returns and next steps but All Clear right now....forgot how peppy this thing was.

Thanks to all for help...