by the way, I'm having almost identical problems (some of which I described in this thread: https://www.clublexus.com/forums/sho...d.php?t=382319), so let me know what you find out. I've got a MAF on order and will let you know if that works. Should get it in a couple of days.

Ran into my problems after washing the engine bay.

 

Not sure, I would just call lexus parts dept. and ask the guy.

 

Got my new MAF in today. I'll keep you posted.

 

Runs great. Replace your MAF. I found one on eBay for like $60 on Saturday. I have a broken one I can sell you.

 

Sebastian,

Did you car end up throwing any codes when you had the problems? (Your initial thread said no codes, but it seems hard to believe that you could have had all the problems you did and never throw a code.) If you did eventually get a code, did you ever run it and, if so, what was it?

Since the only code that my car was reporting was the Main O2 I'm wondering how likely it is that my AFM is messed up. Could a bad AFM result in the O2 sensor code but not the AFM code?

And while I'm at it, how exactly does the O2 sensor factor into the operation of the engine? As I understand it the AFM measures the amount of air coming into the engine - so what does the O2 sensor measure then?

Also, what did you search for the find it on eBay for $60? When I first had my problem I searched eBay and didn't find anything, maybe I used the wrong search terms. Time to search again.

 

http://en.wikipedia.org/wiki/Oxygen_sensor

 

how much is this maf sensor if you buy it thru the dealer?

 

Retail is $968 but yours from Carson Toyota for $789.

 

I never threw a code. I think it's obviously an issue where the car runs well on a "default" type of code after the ECU gets reset, but gradually runs worse as it adjusts to what is a bad/incorrect reading from a sensor that affects a/f ratio. Logically, then, it could only be the MAF or an O2.

I searched for "Lexus MAF" I think and found it no prob. Paid like $60 or something w/priority mail delivery. If you find one that cheap, I say try it. If that doesn't work, just put your old one back in and sell the other on eBay again to get your money back.

But if you cleaned the MAF right before it went haywire, I have to think there is at least an 80% chance that the MAF is the culprit.

 

To answer your question: MAF measures mass of air coming into the engine. O2 measures presence of fuel in your exhaust to adjust a/f ratio. Either one can cause you to run rich. O2 for obvious reasons and MAF because air flow readings affect how much fuel is added, and when the MAF is messed up, most cars will default to a very rich setting (it's less damaging to run rich, plus the car will still run instead of stall like it would if it were too lean).

 

As I said earlier based on the fact the afm sounds fine now and your getting an o2 code now, cleaning your afm messed it up initially but once it dried out good it was fine but in the process running as rich as you did gummed up your o2 sensor. Best guess.

 

BTW, it's a karmen vortex air flow meter (afm) not a mass air flow (maf) sensor.

 

I'm going to say the AFM is still shot. Usually an OBD II car will have bank 2 running lean or rich type code. The OBD I does not. I'm guessing that the meter is still fubar and the code is because the motor is running too rich/lean to keep the O2 in spec.

 

Just wanted to update everybody on where I'm at with this. I didn't win the eBay auction for the replacement AFM I was after so I still haven't replaced it. I'm going try another auction and check the few local junkyards that are around.

I haven't reset the ECU since the last time I ran the code (and the CEL has been on 100% since then) so I decided to check again to see if there were any new codes - there were no new ones, just the 28 that I was getting before.

So I'm still hoping that it's the AFM and that a replacement will work fine. In the event that it's not, how easy is it to replace an O2 sensor? Is there a walkthrough anywhere here? (I searched the First Gen section but didn't see anything.)

 

It's been a little while so I thought I'd post an update of what's going on. I bought an AFM off of eBay and hooked that up about two weeks ago. Car seems to be running better (haven't had any problems with it stalling/going crazy if I rev it) but the CEL is still on. I check the code after a few days of having the new AFM in and it was still just the O2 sensor code.

So, I'm guessing that AFM was probably problematic and that that's now been resolved but that I still need to replace my O2 sensor =(. So that's what I'll need to take care of next.

I tried searching for info on replacing O2 sensors before and didn't come across anything much and I'll do it again but, does anybody happen to have around any good links on doing such a thing?

Thanks in advance for anything on the O2 sensors and thanks again to everybody for their input on the AFM.