Gs400 p0171

Ok guys on old board I posted about this car. I'm still having problems. P0171 lean bank 1 is only code. However as you will see in video both banks are high on stft and ltft. Take a look at vid tell me what you think. I have searched over and over for vacuum leak.. Nothing. Made homemade smoke machine from YouTube. Nothing. When car first starts it stutters and stumbles. If you rev it up to 4k it will stumble and then a puff of smoke out tail pipe momentarily. After that it runs OK.

If you try to mash on gas it will stutter at first
.

Possibly a dirty maf. Have you checked fuel pressure? Sorry, I don't recall the old thread.

If you give it WOT on the road does it hold rich on both o2 sensors?

P0171 lean bank 1 is only code. However as you will see in video both banks are high on stft and ltft.

Yes. To be clear the positive fuel trims indicate that more fuel is added....

Toyota/Lexus are known for bad MAF sensors causing lean fault codes.

I have cleaned the maf with cleaner. But no change. I do not however have someone around with another maf I could try. I'll have to bug my friend to meet up with me to swap mafs sometime to try it.

I'll also get some video of wot. But I thought in wot the stft really don't matter as much.

I'll also get some video of wot. But I thought in wot the stft really don't matter as much.

Indeed! I have some videos for you from the ScannerDanner free channel. Maybe you've watched them, if you haven't sure do Great stuff...





This one has negative trims @ idle and positive trims at higher RPM:



For the record I'm not saying change the MAF sensor...I don't want you to change parts without a proper diagnosis.... That's why we're all here right. At least I hope so :lol: