Hi, I just joined the forum. I've got a 2005 LS 430, with 107,000 miles. The check engine light is on, TRAC off indicator is on, and the check VSC message is displayed. The car has a very rough idle, and the idle is worse with the a/c turned off (feels like it might stall). The car seems to accelerate fine, and seems fine when cruising, but it has a very rough idle when stopped. I have already changed all 8 spark plugs and coil packs with oem Denso, as well as cleaning the MAF sensor and adding bottle of seafoam in the gas tank; none of which seemed to help. I pulled the following codes:

Current Faults:
P0300
P0302
P0304
P0307

Pending Faults:
P0171
P0174
P0301
P0303
P0305
P0306
P0308

I've searched on here for a similar scenario/solution and wanted to see if anyone else has experienced this before or has an idea of what it could be or what I should try next.

Could it the OCV sensors are both going bad, or that the MAF is bad and needs replaced. I'm running out of ideas. \

Thanks for the help!

 

Fixing the P0171/P0174 codes may fix the misfires as they are showing a lean condition. I'd check the vacuum reading using a vacuum gage or the TorquePro app with OBDII dongle. Also reset all the codes and un plug the battery for a few minutes if you haven't done that already. I had a crazy high idle after I cleaned my MAF until I unplugged the battery for 20 minutes (have no idea on what the minimum time is). MAF sensors are not that expensive, but I know I hate changing parts until I know they are bad.

Hopefully someone who has already gone through this can chime in and help you out.

 

Thanks, I do have the torqupro app and the dongle, I'll have to check the vacuum reading tomorrow. Do you know what it should be reading by any chance and what a bad reading is/means? I had the battery disconnected for around 30 mins while I cleaned the MAF and changed the coil packs. The car was still running rough when I started it back up and the codes kept getting tripped as I drove the car around. Definitely don't mind trying any/all suggestions at this point, just want to get the car back to normal. Thanks for the suggestions.

 

As stated above check for vacume leaks, is there any smell of gas? Also there could be a clogged injector, or clogged pick up screen in the gas tank. The pcv, egr system. Super easy check out the plastic intake pipe and make sure it's not loose and just sucking in a bunch of air, for *****s and giggles check the downstream o2 sensors voltage because they control the air fuel mixture they would normally make the car run rich but It is a possibility.