chadis250

I've been reading more about the IACV... Does anyone think I should just replace this? I cleaned the hell out of it, but when i took it out it was so gunked up that the valve didnt even move. It was stuck in position. But once cleaned it seemed at ease. Any ideas?

Alright to update the situation... I just disconnected the exhaust before the cat, and the smoke problem went away. But the idle is still very rough and stalls out after about 15-30 seconds. If i give it gas to keep it going, it tries to correct itself and idle right, but still runs rough. If i put it in drive, it stalls. If i put my foot on the brake, give it a little gas and then put it in drive i can move forward or in reverse as long as i dont let it stall out. Could the seafoam be doing this? I thought from day 1 there was bad gas, but i cyphoned it out and put 2 gallons of 93 in with a but of seafoam. I dont see what else would make it run this way...

Alright where to begin... I have a 99 RX300 (AWD) that suddenly stopped running one day. Got it to start at certain times, with a really bad idle and would never stay on... Yes i've read the other posts on this problem, but i have tried almost everything. I am also familiar with the problems with the 1MZFE engine regarding oil sludging. Currently the car will start up, idle like crap and eventually want to turn off after a few minutes with excessive exhaust both front and back of vehicle (enough to push through exhaust manifold flange). DEF not driveable. This leads me to believe it may be the cat, but i figured i'd see if anyone here had any input first. Ran diagnostic with AUTO X-ray scan tool which popped a Throttle position sensor, but the check engine light wont come on. Before it was popping codes for misfires in cylinders 1,2,3 but changing out the cam sensors and OCV fixed that. I dont think there is an issue with the TPS that would make it have such excessive exhaust and seem like the car isnt breathing and idling like crap. The diagnostic tool displayed TPS at 2% with engine off and 10% with engine on at a rough idle. I suspect possible O2 sensor issues because they were intermittently showing readings but were not throwing codes... Here is what I have done so far (All OEM parts from lexus): Replaced fuel pump and filter Replaced both cam position sensors Replaced both Oil Control Valves (OCV) Cleaned the hell out of the throttle body and Idle Air Control Valve All new plugs and coils Replaced valve cover gaskets Checked and cleaned MAF sensor Ran seafoam in gas Changed oil (fresh) Does anyone think it would be a catalytic converter issue or possibly the TPS or maybe something completely different? HELP! -Chad