Lexus LS430 Problems Engine too Lean What to do?

[fumsinderkidte]

Hey guys,

I recently bought myself and Ls430 2004.

After a short time the check engine light came on together with trc off and the check VSC warning.
I also noticed that the car does not have constant power and takes a long time to accelerate. Also the gear changes are very rough and chaotic. The car doesn't know which gear to chose at what time. I had an 2001 ls430 before and the gears where so much smoother and the power delivery was perfect so I know what I am talking about here.

Also when I rev the car with full power in a parked position it always takes a second for the engine to rev up. Before it revs up it just sounds like if it's clogged or doesn't get enough fuel or something.

I went to a mechanic and we checked on the old and it read the two codes P0171 and P0174 left and right bank engine to lean.

So I changed the MAF sensor. After changing the MAF it felt like the car was accelerating a bit better without hesitation. Still rough gear changes.

Today I checked again if the car would run better with the MAF unplugged. With the MAF unplugged there are a few changes:

-When revving the car with full power the rev counter starts to rise without any hesitation
-With the MAF plugged in the Rev counter first stutters in the first second (feels clogged) and then starts to rise as normal
-also the car shifts a bit cleaner with the MAF unplugged but just a bit. Still a bit of hesitation with acceleration and gear changes
-what I also noticed after driving for a bit longer with the MAF plugged in the car even starts to have clogged accelerations so it gets worse when driving for a longer time

So maby the MAF works but it gets bad readings because there is a vacuum leak somewhere. When MAF is unplugged a friend told me that it takes some general non related values so that's why it probably rans a bit better when the MAF is unplugged.

I hope someone has an idea on what to do next.


Thanks to everyone in advance.

Cheers Guys

[TigerTooth]

Welcome to the LOC!

 

Sounds not so good.

Can you please give some more infos to the car itself?

I mean, how much km are on its ODO?

Are there some other problems you know about?

Are those two mentioned error codes the only ones you get while checking?

 

Am 10.2.2024 um 14:32 schrieb fumsinderkidte:

When MAF is unplugged a friend told me that it takes some general non related values so that's why it probably rans a bit better when the MAF is unplugged.

Yes, thats correct.

 

In which country you are driving?

bearbeitet 12. Februar von TigerTooth
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