Camry Stumbling

[supton]

Been too long, as I managed to lose the ELM327 I had--but I think I was able to watch 02 sensor on that, and I hadn't payed the $5 for the app.

 

[JMJNet]

Try to find bad vacuum hoses.

I agree with the above suggestions to check those big accordion hoses that goes from air filter to throttle body/Intake.
Also, take out that accordion and clean the Intake Valve, spray it with Throttle Cleaner and wipe it out.

Start from there.

 

[Nick1994]

I have found the problem!

Today it was running really bad, even at high RPMs. It finally set a check engine light. P0300, multiple misfires detected.

I checked the spark plug wires and sure enough, one was arcing on the valve cover. The plastic holders for the plug wires broke when I changed the wires when I bought the car, and I didn't bother replacing them. One of the wires must have burned against the valve cover and was arcing. New spark plug wires and it runs like brand new! Need to get those wire holders from the dealership though.

I took out the plugs and looked at them. Numbers 1, 2, & 3 looked good. Number 4 wasn't so pretty. It needs valve guide seals and smokes on startup so I'm guessing that's the issue.

Thanks for the help guys!