Check Engine Light On P1155

[N_C]

Hi,

I have a 2001 RAV4 w/ 65000 miles. Recently check engine light came on. Took it to AutoZone and their OBDII detected a P1155 code (air/fuel sensor bank 1 sensor 2). However, my Haynes munual shows that bank 1 sensor 2 is NOT an A/F sensor, but rather a heated O2 sensor (the less expensive kind). I also read many forums claiming that P1155 is actuall an A/F bank 2 sensor 1. So I'm really confused here. Can someone tell me if P1155 pinpoints the actual sensor or a group of sensors? Also assume I didn't know which sensor is the cause, can bank 1 A/F sensor be used on bank 2?

I see 4 sensors on the cat. manifold. Based on the Haynes manual, the top 2 sensors are the A/F sensor (left is bank 2 and right is bank 1 when you stand in front and open the hood and look into direction of the engine). Thanks.

[anchorman]

Hi and welcome to the club.

You will have to bear with me here because I am more familiar with our system for the 2.0VVTi than your 2.4VVTi.

However, don't get too bogged down with the names of these things as they are all similar devices. The A/F sensors are positioned high in the manifold before the cat and are used to make adjustments to the air/fuel ratio of the fuel injection system. The heated oxygen sensors are positioned after the cat and check the efficiency of the cat (what happened in there as a result of the A/F sensors above). They too can signal changes to the air/fuel ratio. These latter sensors only work when they are hot and need to be electrically heated quickly to give decent information quickly. They work by comparing the oxygen inside the exhaust with the oxygen on the outside.

You could say that the ones before the cat make large adjustments and the ones after make smaller refinements.

It is worth remembering that a fault code could have been stored because at some stage the sensor went outside of its range and for this reason it is always worth cancelling any stored codes as this sometimes puts the light out. There are also several other reasons why a sensor could be showing a fault (it is correctly saying that something else is causing incorrect air/fuel ratio) such as leaky EGR valves or vacuum pipes so just have a look around to see if there is anything obvious.

The DTC code will normally indicate the exact sensor that is faulty or at least showing out of range and not the group of sensors. In this case as you stand looking at the engine from in front of the car it is the top one on the drivers side.

Keep in mind they are sensitive devices (read that as fickle) and although you should start there you can often end up changing more than one and some cases even the cat before you can get them to settle down.

Good luck.

[Steve2720]

Rav4 d4d 2.0 dtc 34 & 97 ideas anybody I suspect turbo vane problem but not sure .

[anchorman]

No 97 is EDU (engine driver unit) that controls the injection and I don't have 34 but it is in the family of injector problems.

Have you done the fuel filter?

[Steve2720]

Hi... Thanks for reply.new f/filter fitted. It seems to be a common problem on these engines, hesitation, at 2000to3000 revs especially under load sometimes putting engine check light on putting f/code 34 on ( turbo, turbo pressure sender s.c.v's etc and occasionally f/code 97 as u say edu,ecu wireing etc ????

[anchorman]

Sorry Stephen, are you asking a question?

There seems to be a lot at the moment suffering with turbo/lack of acceleration on the 2.0 engines. None so far other than yours which point more towards injection. Do you want the pdf for code 97?

[Steve2720]

No thanks I've got access to codes. It seems to be a common problem from what I've read on this forum! Have you ever stripped turbo down on one of these and which s.c.v controls which part of rev range if that makes sense. Any help appreciated .

[anchorman]

I cant answer your question because I don't know. The 2.2 engine pump only has one so maybe the 2.0 valves work in unison to get the volume.

[Steve2720]

Thanks for replying.when I get a bit of time ill do obvious checks and see what I find and put it on forum ! And again thanks.