My car is acting like it’s misfiring and the brakes are intermittently being weird. Like they are working fine and then stiff and not wanting to stop. The line goes to what I assume is the brake booster on the passenger side. There are three lines marked #3, #4, and #* (pound sign and star symbol. The check engine like has been on a few days and pulled codes P0441 and P0446. The check engine like is now flashing. Here are some photos up the vacuum line that’s cut or disconnected.

 

Flashing CEL is due to misfires.

Normally I suggest a good visual to look for issues [broken or cracked line]. But with oil and grime it will be hunting in the dark. Your root cause of the problems could the oil leak but pursuing it upfront can be a diversion.

I can only suggest this order:

Trace misfire [swap plug and coils]
Trace vacuum loss source [smoke machine]
Fix oil leak.

Lexus valve cover gaskets leak around 100K.

Salim

 

If it is the valve cover leaking, also check spark plug tubes.

 

It’s right under where the oil filter is and that valve leads to the dynamic engine mount or active engine mount. There’s three vaccum lines and one of them in the diagram looks to just be plugged which mine is not. Headed to the junkyard today as they have two RX’s! I read somewhere that the active engine mount clicks cause a misfire. Ordered a code reader as well.

 

The active mount simply creates reverse push based on engine vibrations. Misfire and vac leak are not from the mount .... the misfire will cause excessive vibration though and a hose broken off will cause vac leak.

Salim

 

That amount of oil means it is attacking everything rubber and plastic the leak has to be addressed first before you attempt any other repairs.

 

Cleaned all the oil up and put the cap on line #*. Check engine light went off! Then.. it started driving weird and got a whole different code of P1439. The car wouldn’t even drive! Did some research and replaced the VVT and that code and drivability is as smooth as ever. I don’t even know how or if those two things could be related.

 

Once you get the vacuum lines worked out the oil system in the head might have scavenged up some sludge or something that then got trapped in the VVTi solenoid. Which would have caused your DTC. I would suggest you get some engine oil flush and clean out anything that has accumulated over time.

 

Oil pressure is used to move the whole cam to change valve timing. For this your oil needs to be flowing smoothly and the VVT needs to move in proportion to the ECU signal.

Salim