Hey guys, need some help trouble shooting my Lexus is350. I got codes p0031 p0037 p0051 p0057 and p0102. The car is running like crap as soon as I start it stalls unless I give it some throttle. I already cleaned the MAF sensor and didn’t help at all. What I’m confused about is that it’s marking all the o2 sensors but that shouldn’t cause the car to run so bad. Maybe it’s just a faulty MAF sensor any ideas on anything else it could be maybe a faulty gas cap I’ve been reading it’s a common problem in theses cars. Also read that the EFI fuse can cause but I checked the fuse and it was fine.

 

Does your scanner have freeze frame data?

 

No it does not it’s pretty basic just tells me the codes and that about it.

 

Start by checking all the wiring on the 02 sensors I'f you can.

2 up front, and 2 down stream .

Next would probably be check for a short on them with a DMM for resistance.

 

Okay, I have honestly never used a DMM what the reading I should be getting each o2 sensor ?

 

Alright I tried to find the best videos so you can get an understanding.


https://housetechlab.com/how-to-chec...-a-multimeter/

 

Okay so I ordered a scanner that shows freeze frame data and live data. If that doesn’t work I’ll do the whole multimeter thing. I also order a MAF sensor hopefully that does the trick . I’ll keep you updated thank you.

 

So did all of these codes pop up one day or was it a gradual thing? Did these codes appear after any sort of work was performed on the car, and what work exactly?

 

Yup they all popped up I day. I replaced a solenoid from the transmission about 150 miles before that but I doubt that has anything to do with it.

 

Here is an easy way to test an O2 sensor.

 

So I got the the new scanner today did some live readings and I get no reading from the MAF and the up streams sensors. Car is still running very rich and idling is touch order a MAF will update when it gets here. Also maybe the the 2 upstream o2 sensors are making the down streams sensor codes go off? I’m no expert but sounds logical

 

I would assume that since the MAF is not giving off any readings that something is amiss there. Start with making sure that MAF is faulty, and replace that first.

Over-fueling the engine can cause those O2 sensors to fail prematurely.

 

With no data from the MAF its pretty much in limp mode. That is, without knowing the air volume its bound to run pig rich as its protecting itself from harm while unable to run in closed loop mode. That said if it smells stinky the cats are trying to burn all that extra fuel so don't drive it unless you have too.

Get the MAF sorted and the o2 codes may just be fallout from running rich. Make sense?

No, I didn't look them up. =/

 

If your scanner has freeze frame what is the DTC causing the fault?

 

With no data from the MAF, it's likely an instant error from start up.

OP I'd suggest you get Toyota account or www.alldatadiy.com and access the troubleshooting MAF pages and schematics if a new MAF doesn't fix this.

The alldatadiy is like $30 for year vs $30 for a few days.

To my knowledge neither print out a nice easy to read schemo, you have to follow the wires by color, name, grid.