P0155 Still There

[Ghosty]

hi there all i had p0155 code come up for the o2 sensor. Yesterday sensor was replaced for a Lexus part, before this the old sensor was checked and was not giving stable readings. When new sensor was put in it was checked and the other side sensor were checked and both were running good and co2 readings from exhaust were all good. When taking the car out for a drive when i floored the car the light came back on again. I came home cleared the code checking the readings on the sensors again all fine. Once again later when i floored the car it came back on.

i was wondering if anyone else has found this and i have read a lot online about a certain about of key turns relearns the new o2 sensor. Or should i reset the ECU, the only other thing i think it could be is about 2 weeks ago 6 of my spark plugs were changed because didn't have a small enough tool to get the other 2 out. so what are the chances i have a tiny misfire at high RPM hopefully my eBay tool should arrive in the next few days to clear up the problem if it is that.

any help from any gurus out there will be much of help i have found information about the 430 hard to find in the UK

[TigerFish]

Which sensor did you change (location) and which one did they also check? There are four altogether on the GS430, maybe the wrong one has been changed??

[ColinBarber]

P0155 is a problem with the heater circuit rather than the O2 sensor reading itself. Doesn't really make sense that it only comes up when you floor it.

[ColinBarber]

attached is the relevant diagnostic section from the manual for the 4.3 V8

CIP01351.pdf

[TigerFish]

P0155 is a problem with the heater circuit rather than the O2 sensor reading itself. Doesn't really make sense that it only comes up when you floor it.

Both bank 1 sensor 1 and bank 2 sensor 1 were duff on my GS430. If I reset the codes, they would only come back on after full throttle (or very heavy throttle). Had to replace both of them to clear the fault altogether. Both sensor 2's were fine.

[Ghosty]

thanks for replies guys all seems fine with everything going to upgrade the cars ground cables. had a 3.0 accord coupe america again and that seemed to go funny some times if i cant sort it will just bite built have lexus fiddle with it

[TigerFish]

thanks for replies guys all seems fine with everything going to upgrade the cars ground cables. had a 3.0 accord coupe america again and that seemed to go funny some times if i cant sort it will just bite built have lexus fiddle with it

Was it definitely P0155 that showed up again? You only mentioned you reset, but didn't say what code was putting the light on again.

[Ghosty]

Yes was p0155 again comes on after half hour or so normal drivin or just after car being pushed. Going to have alignment done with family friends garage so see if he can work it out

[Ghosty]

well been to mates garage today plugged into some 23k bosch computer and both sensors working a ok no bad grounding or anything. so if comes back on when floor it i will clear the code again and wait for a lexus genuine one to pop up on eBay. As it has been changed recently if i get a lexus one should come out quite easy. have read on america site about some denso ones being a bit funny for no reason.

[TigerFish]

Can you confirm which sensors they are checking, and how are they are checking them? There are four altogether. P0155 is for Bank 2 sensor 1, which is a pre-cat one. I'm just thinking if the post-cat ones are being checked/changed, it would show all good as there was nowt wrong with them. One reason why I'm asking is that the two pre-cat ones are not easy to get to the connectors, so doing a quick check isn't easy. Also, the reason for asking how they check them, is the connectors for the two post-cat ones are under the carpet in the front footwells, so not that easy either.

Both my pre-cat sensors (heater circuits) were duff last year. I bought one from eBay (see item number 180755731260 - no idea of the brand), and the other from www.ecolambda.co.uk (the brand was Walker- not quite as cheap as eBay but none listed on eBay at the time). Both cleared the fault codes and were not genuine Toyota/Lexus parts.

[Ghosty]

Right been back on a bosch machine everything runs fine when floored or idled on machine everything ok. Picked car back up on way home no reason light back on should I check the fuse if so where is it located and under what name ?

Many thanks

[Ghosty]

Sorry didn't add to last post yes was per cat sensor replaced and still p0155 bank 2 sensor 1

[TigerFish]

Was it code P0155 again? No reason to assume it is definately the same code, could just be coincidence.

Which sensor is it they changed? Looking from the the front of the car, what was the position? i.e. left/right hand side/downpipe/underfootwell, that kind of thing. Just to make sure they are changing the right one :)

Which fuse do you mean? If the fault codes have been cleared, then there should be no reason to reset the ecu. I would tend to lean towards wiring to the said sensor if it is still playing up.

[Steve]

Rick, do you know the location of the 4 sensors?

[TigerFish]

Rick, do you know the location of the 4 sensors?

I do mate. The reason I haven't said Bank 2 sensor 1 is "here", is if someone has changed the wrong one and doesn't want to admit it, they will just say "yeah, that was the one". If they have to describe which one it is, it will either be the right or wrong one.

[Ghosty]

well now you say that i live in fear i may have changed the wrong one i changed the passenger one as it was original lexus and the one drivers side looks almost brand new.

if i have changed the right one what other causes could there be. I need to change coolant as have the water running noise when i use the heater so have a little air lock. maf and throttle body have been cleaned out brand new iridium plugs in, wiring looks like just come out of factory only covered 48k.

[Ghosty]

also this is going to sound very amateur but on the website you provided there is a differences between front left and right. now which side is drivers as it says direct import from US have they kept it US drivers on left or UK drivers on right. Wait confused myself so if i do in fact need drivers what side do i need from there site.

got to say many thanks everyone on forum is great with little tips my local Lexus dealer arent to helpful. Had brakes apart the other day went to dealer to get new slide pin and the looks i got off staff for standing in show room with oily hands and face. Never found that with Jaguar their parts depart consisted of 3 guys that knew everything about the cars without the need to look it up on computer and normally covered in oil themselves.

[TigerFish]

Sorry mate, wasn't trying to put you in fear of anything. I thought if a garage changed it, they might mug you off if they had done the wrong one.

Looking from the front of the car, cylinder one is the first cylinder on the right hand side (passenger side in the UK). Bank 1 refers to the bank with No1 cylinder in it. Sensor 1 is pre-cat (in the downpipe), sensor 2 is post cat (under seat area). Unfortunately for you, Bank 2 sensor 1 is the drivers side front one, not the passenger side front one that you have changed. Sorry to bring the bad news mate.

[TigerFish]

also this is going to sound very amateur but on the website you provided there is a differences between front left and right. now which side is drivers as it says direct import from US have they kept it US drivers on left or UK drivers on right.

The engine is still the same in the UK or US, so Bank 1 is still the same bank, as is sensor 1 or 2. As long as you order them by bank and sensor, you won't have any problems getting the right one.

[Steve]

i think i am having same problem.

I powered my 430 on a dual carriageway as i do a lot of short journeys and the CEL came on. I reset it and came back on after 10 mins.

I assumed it was a dirty MAF sensor. The car did not go in to crawl mode.

Rick, when i get the codes, if it is one of these sensors are they easy to fit?

to obtain codes can i use the paperclip trick?

[Ghosty]

Right just to dumb it down even more for me which side is bank 2

[dave1]

Right just to dumb it down even more for me which side is bank 2

Looking at Rick's post it appears that Bank 2 is drivers side.

[TigerFish]

Right just to dumb it down even more for me which side is bank 2

Looking at Rick's post it appears that Bank 2 is drivers side.

That is correct.

[TigerFish]

i think i am having same problem.

I powered my 430 on a dual carriageway as i do a lot of short journeys and the CEL came on. I reset it and came back on after 10 mins.

I assumed it was a dirty MAF sensor. The car did not go in to crawl mode.

Rick, when i get the codes, if it is one of these sensors are they easy to fit?

to obtain codes can i use the paperclip trick?

When it comes to fitting, it depends. Both Sensor 2's should be relatively straight forward to get to the connector under the carpet in the footwells. As long as the sensor isn't corroded solid, they should come out easily enough. Bank 1 sensor 1 is not bad, if a bit fiddly to get to the connector. Again, corrosion allowing, it should come out. Bank 2 sensor 1 was a real pain on mine. Connector is back under the under tray, so that needs to come off to get to it. The sensor on mine was corroded up very tight, so to get extra space for leverage, I ended up taking the cross member off that runs under it. I guess it can be made slightly easier if you saw/cut the sensor off so that you can get a standard socket or spanner on it. Unless you have O2 sensor sockets or wrenches, I guess you would have to do that anyway (or cut the lead off at least).

No idea on any paperclip hacks for code reading, I have a cheap code reader which does the job. Some code readers do trigger a vsc/trc error to come up, there is a paperclip hack for clearing that fault code. If you need it, I can grab the piece of paper I have left in my code reader case. Luckily my reader doesn't cause the vsc error, but the one the guy had that I bought my GS430 from put the lights on when I picked the car up. Caused some concern/panic to start with until I found why it had happened.

[Ghosty]

Well guess who feels silly know although testing sensor one drivers side everything reads ok. Well as I borrowed an O2 spanner last time think will go down the route of cutting of and getting breaker bar in there. Lucky ad I said before she looks not too old so well least not original and wiring boot is all clean. So should come out better than the last one.

Thank you for all your help need to order new one and see how go will repost when all is conpleted. Also going to do a guide on installing aftermarket reversing sensors in next few days only option my 430 seems to lack.