1997 Camry P1135 CEL on - What is the right part???

You "might" need to change both sensors. Yes, they are expensive. The reason the manifold replacement possibilty was brought up is because sometimes the threads are damaged when removing the old sensor, this is rare though. I'd be shocked if a PCM is needed.

That trouble code is P0135, not P1135.

Toyota's supplier is Denso, not "Danso." As to whether your vehicle has California emissions requirements, check the original window sticker and under the hood for the emissions stickers. It will say "federal" or California.

The problem with some aftermarket O2 sensors is that they have "universal connectors" which means that you have to cut and splice wiring.

If you know "lefty loosey, righty tighty," can bend over enough to tie your shoes, can hold a wrench, and can figure out how to unplug the electrical connector, you can probably change the O2 sensor yourself, especially if you use an OEM part. Unplug the old sensor, unscrew the old sensor, then reverse the process.

Ray, Thanks for the information. I went and checked with a local mechanic he suggested that I would be better off getting a Denso sensor from the Toyota dealer instead of getting an off the market part (even if it is a denso off the market - he says they break too soon). And to my surprise apparently all Northeast cars, after 1995, have the CA emission standards. Interesting to note.

The fault was P1135 I am pretty sure of it I noted it down when we read it.

P1135 A/F Sensor Heater Circuit Malfunction (Bank 1 Sensor 1) (Toyota)

Also, Toyota uses what is called a Air Fuel sensor in the front banks and O2 sensors in the rear banks. I wish it was the O2 sensor that broke, which is like $99 but this one is like $250 and must be obtained from the dealer for it to work properly, I was told by a local mechanic who I trust.

Thanks Andy

Ray O wrote:

Check this site for the correct meaning of the codes,

P0135 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)

P1135 A/F Sensor Heater Circuit Malfunction (Bank 1 Sensor 1) (Toyota)

I may be mistaken, but I'm pretty sure the A/F Sensor and the O2 Sensor are the same thing. Some O2 Sensors are heated, and some are not. Yours is the heated variety, and the heater is broken. Let us rely on Ray O to confirm this, he works with this stuff all of the time and he will know if my theory is correct. A failure of the O2 side of the sensor will give the P0135, a failure of the heater element side will give the P1135.

There is a school of thought that says the interconnecting wiring can be the problem, and the connectors have failed on occasion. Personally, I like to think that the connectors and wires will survive much longer than 10 years, and I go with the component as the probable failure. Having said that, the failure areas of the wiring are generally at the connector, and while going after the component, the connector is along the way so give it a look.

The sensor has a heater element inside, and the computer can look at the circuitry of the heater to determine if the heater is working. Heaters get hot, that's what they are for. And, the heat makes them brittle and they fail.

If you can replace a spark plug, the odds are good you can replace the O2 Sensor. Ray says that the connector on the aftermarket (not, off market by the way) parts can be the wrong one, causing one to splice wires. I have never run into that one before, and my guess is that if the connector is wrong, then the part is not the right part for any number of reasons. I would pull the failed part and carry it with me to the parts store to compare with the replacement part.

Actually, I hardly ever work on this stuff any more because it hardly ever fails.

You are sort of correct. An O2 sensor and A/F sensor are not the same thing in that they operate on different princicples, but they both measure the air/fuel ratio.

When the system is cold, the sensors do not give accurate measurements so the computer sets a default air/fuel mixture. During this warm-up period, fuel economy is lower and emissions are slightly higher. In order to get the sensors up to operating temperature more quickly, they have heaters built-in so that the system can start setting air/fuel mixture based on actual conditions instead of a default condition.

~~~~~~~~~~~~~~~~~~~~~~~~~~~ If it's this easy, would it not make sense to let the dealer's mechanic do it and pay likely the minimum labor charge, if the owner is fearful of not doing it right ? I'd think it would be worth the $35 or so to let the dealer bear the responsibility if the mechanic broke it on installing it....but then again, perhaps once in the hands of the dealer and his service writer, one would feel like he was in one of the seven circles of hell.....

It also depends on the value of one's time, whether one enjoys working on cars, and whether one is capable of figuring out if the tab has to be pressed or pulled to take apart the connector.

Sewing, cooking, gardening, woodworking, etc is easy and even enjoyable for some people, while others pay others to have this stuff done.

Sorry, I meant that they essentially do the same thing, mix the air and fuel to acheive a desired result in the exhaust stream.

I was thinking they lived in the same place within the system, and that an engine would have one or the other but not both.

So in other words it is Air Fuel Sensor related problem right?. That is what my mechanic is asking me to do. Or can this code indicate any other related problems. Will this go away if I put my new Air Fuel Sensor (Toyota part# 89467-33011) which I bought today. [It cost me close to $250 but I just found out it is also available on the web for lot cheaper like $100ish - same part, same part#).

Thanks Andy

Jeff Strickland wrote:

Yes, it is MOST likely the A/F sensor itself. And, it's the heater element built inside of it if you need that much resolution.

Personally, I would have gone with the aftermarket and avoided the dealership, but I like to take my chances.

Correct on both counts.

There is a fair chance that the condition that is turning on the check engine light will go away if you install the new air fuel sensor. There is also a chance that the problem is caused by a loose connector or problem with the wiring for the system. BTW, it may take a while for the check engine light to go off by itself, if at all, you may need to use a code scanner to clear the check engine light.

Thanks Ray and Jeff. I got the part and got it fixed. 200 miles later the light statys off and the car passed emissions test. My local mechanic charged me only $20 to change the part (the part itself cost me $230 though) but still I saved about $175 off the price quoted by the dealer.

On a related note, I saw another post where someone was suggesting to reset the OBD II codes and after wiping them out his car passed the emissions test. But when I fixed my sensor I went for emisions test after about 20 miles or so and it failed as they cant read the ODBII computer on board (I had the mechanic reset the Check Engine Light as I was taking the car for emissions test right after this was fixed).

Thanks for the help guys Andy

Jeff Strickland wrote:

You're welcome! The computer has to record 2 specific types of trips without detecting any problems before it is ready for an emissions test.