1999 Avalon Random misfire Random Cylinder Misfire P300,P301, P305

[edge10]

I would start with the VVT solenoid for bank 1. You can get misfire codes when a solenoid starts getting lazy without getting the specific codes for the VVT, then when it gets bad enough, you'll see like P1130 and P1349.

This 1mz-fe does not have vvt, I think that introduced a year or two later. It does have a variable intake.

 

[edge10]

Any recommendations for a dongle? Many bluetooth seem to have problems, so maybe a wired is better.

 

[Lawnman23]

Any recommendations for a dongle? Many bluetooth seem to have problems, so maybe a wired is better.

I have a few wired ones but also this one:
https://us.bluedriver.com/pages/bluedriver

No subscription stuff, just buy once and install the app on your device. Works fine for live data streams.

 

[zzyzzx]

Any recommendations for a dongle? Many bluetooth seem to have problems, so maybe a wired is better.

Techstream, Techstream adapter (even a cheap one will work) and a laptop.

 

[edge10]

I've seen improvement after 1 oz. per gallon of Techron. After 20 miles no MIL and misfire is nearly gone except a slightl amount at throttle tip in and when climbing a hills at about 1500 rpm. Not enough to throw a code.