'99 Es300 Codes P0300/1/3/5 And 1130 1133 1135

[KenH]

Both CEL and the TRAC lights are on all the time. Am I correct in thinking that these codes, P0300, P0301, P0303, P0305 along with 1130, 1133, and 1135 could all be caused by the bank 1 O2 sensor?

I'm thinking that cylinders 1, 3, and 5 are on bank 1 and if the O2 sensor there is defective that could cause misfiring. Correct?

I'm also thinking that while I am getting my hands and arms all scarred up getting up into the back of the engine that I should replace the plugs. Correct?

It is a 1999 ES-300 with 84,750 miles on it.

Thanks. I did search the forum, walked thru about 10 pages of messages (search doesn't really work & learned a lot, but didn't see this exact combo.

[Toysrme]

A-la Toyota's 1994 Camry Repair Manual

It could be either/both. The coils & ignition sensing equipment are ruled out by default, so skip checking them.

I would start by replacing the o2 sensor & resetting the ECU (remove EFI fuse a second & replace). You don't have to remove anything to get to either o2 sensor. Tho no one is going to talk you out of taking the upper intake manifold off, cleaning it & it's associated components (Throttlebody, ISC/IAC, EGR valve) by hand (good way to ensure future reliability & regain lost horsepower from carbon build-up).

[KenH]

thanks, I'll pick up a sensor tomorrow.

The owners manual says to change plugs at 90K, will do those also.

KenH

[jahwarrior]

what do you all think of aftermarket o2 sensors??