BADFNZ

iTrader: (2)

So yesterday I washed the IS350 and did some cleaning under the hood. All I did was wipe down the plastic covers with a rag. When I'm done, I start the car and it runs like ****. The idle is surging and I get a CEL. I look around and notice the plastic shell around the MAF harness is loose, but the plug is still tight. So I unplug the harness to see if it gets better or worse, but it stays the same, which tells me I've probably found my problem. I had other stuff to do that day so I leave it be for now.

So the next day, I go to start the car and it'll run for .69 seconds then die. I plug in my scanner and it's showing P0102, P0103, and P0113, all MAF and IAT codes. But now I'm not sure if some of these showed up because I unplugged the harness or not, but oh well. So I take out the MAF and clean it with some electrical cleaner, but there's no change.

So now I'm to the point where I need to check the wiring. There are 5 wires and I found this thread https://www.clublexus.com/forums/is-...o-the-ecu.html giving the pin out for the MAF. I'm guessing I should see 12 volts on all but the 2 grounds? So if the wires all check out, anyone have any other suggestions besides the MAF just randomly going **** up? It seems random that I'm toying around under the hood and it just stops working. I did a search here and found one case of a MAF going bad so I guess it's possible, but doesn't seem common at all. And no, the car is not under warranty.

XhyDra

iTrader: (8)

My advice would be to go to your local autoparts and get a can of crc electrical cleaner and crc MAF cleaner, then spray clean the MAF and the connectors as well. Unplug your battery and give it a go again.

BADFNZ

iTrader: (2)

I've already cleaned it, but didn't disconnect the battery.

BADFNZ

iTrader: (2)

Anyone else?

XhyDra

iTrader: (8)

Ok so just for reference, exactly what method did you use to clean the MAF. Did you also disconnect the MAF from the wire harness before cleaning? And did you spray the wire harness connector with the cleaner when the battery was plugged in?

BADFNZ

iTrader: (2)

I disconnected the MAF from the harness when I cleaned it, reinstalled it, then disconnected the battery. After this, it actually starts and runs now, but now it's showing P0172 and P0175, rich condition on both banks, and I can smell the gas to confirm this. I think the rich condition is only happening at idle, because the car runs fine, but when I give it gas, it hesitates for a split second then goes. I'll reattack later tonight.

Gville350

iTrader: (10)

MAF cleaner.

BADFNZ

iTrader: (2)

Have you read the thread?

BADFNZ

iTrader: (2)

Reattack.

I checked the voltage of the 5 wires going to the MAF and here are the results:

1- 1.5v
2- N/A (ground)
3- 13.5v
4- N/A (ground)
5- 1.5v

So it looks like the MAF is getting power (pin 3), but my question is, should pin 1 and 5 be showing 13.5 also or is 1.5 normal? I know these are the IAT and ECU readings, respectively.

lexusis305

iTrader: (2)

Did you wet the maf or sprayed it what somethinge and right after its going crazy replace the maf or swap with a friend to make sure its bad. I replaced my maf do to the wrong reading it was lean it and runing like crap I replaced it and back to normal

lobuxracer

iTrader: (2)

Sounds like you got water in the backshell and it's wreaking havoc with the readings. If it runs now, but runs rich, it sounds like THA isn't working right.

Usually this connector is pretty water tight, but it could also be you have a defective connector shell.

I'd try WD-40 in the connector to the MAF. The WD stands for water displacing, so it's the right tool to use for something like this. MAF cleaner and electronic connector cleaners may not get all the water out. If you have compressed air (not the dust off stuff, but real compressed air), you should blow it out first, WD-40 it, then blow it out again and reconnect.

BADFNZ

iTrader: (2)

Fixed it. I just cleaned the MAF again and disconnected the battery. No more problems.

JDMis350

iTrader: (1)

so was it xhydra's method for cleaning it that worked for u? i was gona say i had a similar problem wit the car shutting off and dying after a second of starting it due to the MAF and i tried cleaning it and nothing changed so i jus bought a new MAF sensor. No problems now.

Gville350

iTrader: (10)

LOLz! 10 char