joegreen

Hello, So its time for my nys inspection and i need to get these codes fixed. Also the car has no power and my gas mileage is horrible. So here are the codes. p0120-p0136-p0440-p0441-p0446.
First off i tried doing some research but am having trouble finding the correct o2 sensor to plug and play. Second could p0120 indicate a bad throttle position sensor? Could the rest of the codes be caused by the bad o2 sensor? Also i have a body code b2796 no communications in immobilizer system. What does that mean? Thank you for all your help in advance.

tomf

Need to know the model year for help on the sensor. You'll want the bank 1 sensor 2 sensor. Also referred to as the downstream sensor. Denso refers to it as rear downstream or if there is only one downstream sensor just downstream. Go here http://densoautoparts.com/find-my-pa...icle-selection , the Denso website to get the part number you need.

joegreen

vehicle is a 2000 es300

tomf

From the Denso website this is the part number for the O.E. downstream Oxygen sensor: 234-4137. It can be bought on Amazon for $48.

Did all these codes appear simultaneously?

For your B2796: This code is stored in the memory when a key that does not have a transponder chip is inserted or if communication between the key and transponder key ECU assy is impossible.

joegreen

the cel has been on for a while. I am not sure if all of the codes came on at the same time. I bought a new key through lexus and tried to program the new chip in it but could not get it to work. I ended up putting in the old chip. Maybe that's what caused the body code. Also while they key was broken i had to use my old solid key that i assume did not have they chip in it. Its the key that will only open the door and start the car. It will not open the trunk. Thanks for the 02 sensor link. Ill order that right away.

tomf

Since you don't have a master key it's likely you will have to go to a dealer to get something that works. Check out this link. http://www.toyotanation.com/forum/10...ansponder.html It's likely the same system as on you ES300.

Here's a link that might be helpful from the above linked thread. http://www.automotiveforums.com/vbul...58&postcount=7

Good luck.

joegreen

I haven't bought the 02 sensor yet. Autozone shows the sensor being closer towards the engine but the sensor you suggest is located after the cat.

joegreen

never mind. i found the location on mitchell on demand. you were right.

tomf

Here's a link on how to replace the downstream sensor: https://www.clublexus.com/forums/rx-...sor-2-diy.html

The O2 sensor is located generally under the driver's seat. The wiring comes through the floor and the connector is under the carpet. On my ES300, I just cut the carpet to access the connector. The cut is under the driver's seat and can't be seen.

joegreen

I cleared the engine codes the other day to see what codes would come back. None of the codes came back except for one new code. p0171. I did a little reading and cleaned the maf sensor. Here are the symptoms the car has. It has to crank over a few times before it catches and starts. It idles fine. If you stab the accelerator quickly it bogs hard and then picks up. If you floor it from a stop it has no power. If you are cruising and you floor it it downshifts but you don't pick up any speed. The car is fastest if you give it part throttle. Also the fuel mileage is horrible. Thanks for everyones help so far. I don't mind replacing parts as long as we get somewhere. Also any test you want me to perform let me know. I am not unfamiliar with vehicles. The car has 155,000 miles on it. Timing belt was replaced at 92,000. Spark plugs were replaced 30,000 miles ago.

joegreen

I tested the maf sensor with my dvom. The voltage moved up and down linearly. It idled around 1.2 volts. When i stabbed the throttle it bogged but the maf reading jumped up to 2.1 volts. I do not think that thier is any problem with the maf.

PFB

Your symptoms also mimic a clogged or partially clogged catalytic converter.

Also check your PCV valve. At least that's an easy 5 min check.

Phil

joegreen

ah cat. that's the last thing i want to hear. Lets just say i need a cat, do i need a factory one or can i weld my own aftermarket one in.?

joegreen

ok so i replaced the fuel filter the other day. Its the first time it's ever been replaced. it has 150,000 miles on it. I reset the codes and the car did better. I am not sure if it was the fuel filter or resetting the codes. Anyway my o2 sensor arrived today. I haven't had an 02 sensor code ever since i cleared the codes but i was wondering if i should replace it anyway.

PFB

Wait another week or so. Or at least 200 miles. See if it comes back

It probably will. So you can deal with it at that time