jbrazil

2005 GX 470 warning lights VSC OFF, VSC TRAC, Anti Skid, and Check Engine lights came on and the codes P0 172 and P0 175 came up which indicated 2 oxygen sensors needing to be replaced and that was done. Drove vehicle about 100 miles or so and all above lights came on again but then went off after driving and starting car 5-6 times- car drives fine, perfect. Took back to service center to check if codes pulled up and the same 2 codes, P0 172 and P0 175....service guy did some more serious looking around and detected a bad mass air flow sensor and replaced it (no cost for labor) and he drove vehicle alot felt all was well and of course my wife drove 100 or so miles, lights on again.... any feedback from any owners with these warning lights issues and repairs would be great!!!
Thanks-

BurgBoxstr

find a new mechanic quickly as this guy is just playing mechanic on your dime.

First off, replacing the MAF takes about 5 minutes including removal of plastic engine cover on passenger side (it's only held in w/ 2 philips-head machine screws just aft of the air filter) so he shouldn't have charged you any labor.

Secondly, MAFs aren't cheap at all and he should have tried cleaning it first before simply replacing (it's all of ~ $7 for a whole can of QD electronic cleaner at any parts store). Plain and simple, b/c replacing it didn't fix your issue, the MAF wasn't the cause and you could put the old one back in...

Anyhow, since the same codes are consistently being thrown you need to first go back to the O2 sensors and make sure the new ones are OK and were installed correctly. Know it's kind of odd you are also getting the Anti Skid light too as I thought you'd only get both VSCs and the CEL. Furthermore, it's not common for both O2 sensors to go at same time.

Was/is the CEL flashing at all or did it just come on?

Additional thoughts... go to an Advanced Auto or the like and have them pull the codes (most of the national chains do this for free) and report them back here.

Any specific conditions when the light came back on or just after ~ 100 miles? i.e. under hard acceleration, at higher altitude, going down hill, etc...

The codes you gave are generic running too rich left and right bank. As such, it could be a host of issues. You don't want this guy just replacing all possible problems until he finds the correct one b/c he can test each to narrow it down...

BurgBoxstr

Also, see this thread in the RX sub-forum as to why you don't want this guy to just keep guessing. It could be any host of issues including ECU/software related....

https://www.clublexus.com/forums/rx-...172-p0175.html

jbrazil

CEL just comes on prior to the other 3 lights, has never flashed and all lights will go off after vehicle is driven ~ 100 miles or so.
I appreciate the insight & information- have used same mechanic 2+ years with our LS 430 and service has been perfect-but I'm keeping in mind your comments as we move forward with this GX issue-
Now scheduled to take vehicle this Friday to original dealership and will see what shows there.

bcjames423

I am encountering the same problem. The dealership here in Tampa wanted to charge $300 to fix a turn signal bulb. I told my wife NO>> and changed it myself. It was on the drivers side and I had to pull the battery to do it.

BTW the manual and the computer at Advanced Auto Parts said that the bulb should have been a 3157/4157NA (NAK in the Manual). It ended up being an 1156NA.

The turn signal is working now, but Im getting the indicator lights you described above. The engine is idling low and has stalled a few times too.

Is there some kind of manual reset I need to do? Thanks.

BurgBoxstr

bcjames423-

Good info on the bulbs but unfortunately based on your idle description, they are unrelated problems that coincidentally just appeared at the same time.

So, first off you need to find out what specific codes your GX is throwing as the VSC Off, VSC Track and CEL combination can mean many different things. Mine all went off when the rear ride height sensor went bad. They also went off when I had multi cylinder misfire (w/ codes P0300, P0302, P0303). Otherwise, we'd will all be just taking WAGs as to your problem.

Go to a national parts store (AutoZone, Advanced, PepBoys, etc.) and have them use their OBDII scanner to read the codes for free. Then, for more help and the benefit of others in the future, start a new thread w/ your issues and list the codes. They'll be P-xxxx (x is numeric)

bcjames423

So...

Went to Adv Auto Parts. Checked the battery. Idle was 14.4V and MAX was 13.9V. My cold cranking amps were up to 750. So, it wasn't the battery.

The code that came up was P0101 (Mass airflow intake). He cleared the code and the X-mas tree from hell went away. No actual work required. Will continue to monitor and will let you know if it pops back up. Thanks.

BurgBoxstr

Did you pick up some QD Electronic Cleaner while there to clean the MAF? As stated above, you should try cleaning it before considering replacement. Also, when was the last time you changed air filter? Are you using and aftermkt one like K&N (which are notoriously over oiled out of the bag and ruined more than a few MAFs)?

If you do need to replace, definitely DIY as it's only a 5min job (as you'll see when cleaning). Not sure if www.autohausaz.com carries them but I've gotten OEM MAFs from them for much cheaper than anywhere else.

Good luck

lepoch

This can be caused by a loose gas cap too. I got a new gas cap after several of these christmas tree alerts...and that fixed it.

misergx470

I am having same issues on my 2006 gx470. Bought used at 48,000 miles and have only had trouble since weather has gotten colder. After owning 30 days, same lights came on for me with a code P0158. Had Bank2 Sensor 2 replaced and light went off for a week and just came back on. Took to local mechanic and now codes is P0051 which is saying Bank 2 Sensor 1 is bad. I am worried there is an underlying issue and these replacements are expensive... any advice?

BurgBoxstr

jbrazil-

Good luck tomorrow w/ your dealer and please let us know the outcome as it will help others in the future.

Thanks

ROSCOGX470

I had the same problem as you. You probably have an eary build 04(11/03) When buying bulbs, filters etc. for an early build 04, use the info for 03 as they changed things around for the later built 04's(4/04)You can check the build date on the inside of the drivers door where the VIN#'s are located. Lexus dropped the ball here, Why not wait to change items for a different year?

ROSCOGX470

I also had the identical thing happen here as well. They needed to replace the catalytic converter. Apparently, I had an exhaust leak by the engine pipe and it was enough to through all the codes you are seeing. The engine pipe and catalytic converter are all one piece. If you notice a slight "ticking" sound from the front on acceleration than you might be in the same boat. I had 70k miles and a aftermarket warranty and Lexus replaced the converter free under the emission 100k warranty. Check it out.

jbrazil

Picked up vehicle from dealership repair center today-they kept it for couple days and the final word was "ECM learned memory from defective sensors out of range with new sensors. Most generic diagnostic scan tools of aftermarket repair facility can't clear learned ECM memory"
So even though the defective sensors were replaced apparently there is some specific process with clearing the codes.
So it was worth the trip to dealership to bring closure to the recurring lights-there was no charge and so far so good -no lights at this time and vehicle running great.
Thanks for the feedback and comments here!

jditom

I had the same thing happen to me twice. Both time I cleared the codes and read them with a scan guage.

I bought a new OEM gas cap at my Toyota dealer for about $20. Cured the problem. You can really feel the much tighter fit on the new rubber on the cap.