Hello CL,

To start, I've owned my RC for just about 2 years (October) I've had no issues out of the car until now.

Mods include,

PPE headers (catless)
Invidia catback exhaust
Top speed carbon fiber intake
RR racing heat shield
K&N drop in filter

On to my issue. I decided to do a deep clean of the car the other day, took the wheels off, cleaned the wheel wells, ceramic coated the rims, the car, etc. Took my time and ended up taking me a few days without starting the car. After I finish I'm excited for a drive! I start the car and it immediately started acting weird. Extremely ruff start, idle is like there is a large cam in the car. I don't think to much of it and run to the auto parts store for a few items. Driving was *****, sitting at the light the car died.....CEL & trac pop on, and I get a message that the engine has stopped working and to pull off to the side of the road. WTF. Restart the car and limp it back to the house, stick a scanner on it and get codes P1170, P0170, P0174. From what I've read on the forum its some kind of issue with a vacuum leak and/or MAS air flow sensor. Now keep in mind, I've had these mods on the car for over a year and have had no issues.

From here, I take apart the intake, clean the K&N filter, clean the MAS airflow sensor, clean the throttle body, reassemble same issue. Disconnect the battery, look for loose vacuum lines, none. Run on my hand on as many lines as I can to see if any are cracked. None that I can find. I jack up the car looking for possible broken O2 lines, none. Reconnect the battery, same issue. So, I take it to the stealership and they can't even figure it out what's wrong with it.

I find it hard to believe it's something major with only 60k miles on the car. I've been through the forum up and down with the codes but can't seem to find a concrete answer on what a fix may be. Any insight would be greatly appreciated.

 

Check the nuts holding the headers to the engine. I got similar codes before, yours points to bank 2, mine was bank 1. A few nuts had backed off causing an exhaust leak at the manifold, which the O2 sensor picked up as "lean". Turns out my RR engine mount wasn't torqued properly causing a bunch of movement. Issue popped up at a track day after having headers for nearly two years.

If you have no leaks on the intake, check the exhaust side. Also since you mentioned a deep detailing, make sure you didn't water in some connectors. That could be causing things to not read correctly also.

 

Almost a week later, lexus found a loose vacuum hose. Nothing to see here.