amanda

hi, guys. i have a 2000 es300. 84K miles and never had any real problem with it (except when i put on some dang falken ziex tires - but enough about that). day before yesterday, hubby said check engine light came on and when i went to look, there was both the check engine and the TRAC OFF lights on. i turned off the ignition and the car sort of "sputtered" (?) and the battery light came on momentarily then the engine turned off.

i was alarmed and restarted the engine which seemed to have some issues but did turn on. subsequent turns on/off were fine.

yesterday, i took it to the mechanic and he said a battery cable was loose. he also said i needed a new MAF sensor and forgot about the TRAC OFF light but when i mentioned it, he put the car up on a lift and said it might have been a fluke when the check engine light came on because of the sensor.

i got the check lights turned off and things have been driving ok. but i think it's going through gas like crazy but i don't know if that's just my imagination.

so my questions are:

1) could i have gotten the MAF sensor error code because the loose battery triggered a malfunction which was interpreted as MAF failure when in fact it was just loose battery cable?
2) how frequently do both check engine and trac off come on together?
3) will i get a new check engine light if i keep driving and the MAF is indeed malfunctioning?
4) is my car eating gas like crazy because it needs a new MAF senor?
5) do i need a new sensor or can it be cleaned or should i not bother and just replace?

thank you!

MikeLex

First of all, did your mechanic pull the fault codes?

amanda

yes. that's how he got that the MAF sensor was off. gees. this post is not looking too hopeful, is it?

amanda

does anyone have any ideas?

ASG14

iTrader: (1)

Need to know what the codes were before I can even say anything.

GS4_Fiend

iTrader: (22)

Post the codes up so we know what we are dealing with.. Also, I recommend cleaning the MAF sensor first before changing it.

amanda

oh, sorry. it came up with

P0171


thank you!

PlatES300

iTrader: (1)

I've had this code on my car for almost a year now. I already replaced both o2 sensors to no avail. Next up is the MAF sensor and I'm hoping that will fix the problem. Keep us updated.

MikeLex

1) could i have gotten the MAF sensor error code because the loose battery triggered a malfunction which was interpreted as MAF failure when in fact it was just loose battery cable?
A: Very unlikely

2) how frequently do both check engine and trac off come on together?
A: Very frequent. The ECU turns off the electronic traction control when it detects some specific malfunctions in the engine.

3) will i get a new check engine light if i keep driving and the MAF is indeed malfunctioning?
A: Yes

4) is my car eating gas like crazy because it needs a new MAF senor?
A: Your engine is eating too much gas because the fuel trim is out of spec (too lean - P0171). Possible trouble areas: Air intake (hose loose), fuel line pressure, injector blockage, heated oxygen sensor malfunction, coolant temp.sensor and, of course, the MAF sensor is perhaps the best candidate in your case

5) do i need a new sensor or can it be cleaned or should i not bother and just replace?
A: A new unit is around 180 bucks and you don't even know if it is the culprit. Why don't you buy a bottle of MAF cleaner and give it a try?

GS4_Fiend

iTrader: (22)

Only 1 code, P0171? That's Lean on Bank 1. MAF sensor is not related because it would cause 2 banks to go Lean at the same time. The intake gasket are on bank 1 and they do leak. Get it smoke tested to confirm the leak. We can rule out the oxygen sensor since you already replaced it.

amanda

is this a standard thing mechanics do? he said it'd be $110 for diagnostics. so should i just replace the tube instead?

thank you.

amanda

that was a different poster. i haven't replaced my oxygen sensor.

amanda

is that pretty easy to do? i thought i read somewhere that i could do it wrong and cause a bigger problem?

also, just buy it at autozone?

thank you!

MikeLex

Here is the DIY: https://www.clublexus.com/forums/es3...af-sensor.html

amanda

just got around to doing this today.

[url]https://www.clublexus.com/forums/rx-first-generation/515386-diy-maf-mass-air-flow-sensor-cleaning.html[/url

much easier access. mine didin't look very dirty at all so i think i am going to have to resort to replacing the dang thing. will post an update.

but i have driven around about a week (maybe 25 miles of driving or so) but i have not gotten the error code again. does this mean the code was a fluke?

thanks!