1996 850T P0133 Code & fixes so far

kimothyanne · Post by **kimothyanne** » 20 Jul 2015, 07:09

Hi y'all,

My 1996 850T threw a P0133 code which according to my scanner meant an O2 sensor, 2nd bank. Given the age of the car I had both sensors replaced. My mileage went up from 12 mpg to 18.

I drove it 30 miles and the check engine light came on again. Yes, it was the same P0133 code. I decided to clean the MAF sensor. In the process I dropped one of the screws to the MAF housing deep into the engine and have been unable to retrieve it.

1) Does anyone know what size (other than a T20 in this case) screw it is? Length, thread spacing and the like?

2) Also, any ideas as to why the car continues to throw the P0133 code?

Thanks in advance,
kimberly

Post by **erikv11** » 20 Jul 2015, 07:55

(1) It is like a wood screw, it screws into plastic not into a threaded receptacle. I would pull the other screw out and take it to the hardware store, ask them if they have a similar thread. I have a couple extra MAF screws from the junkyard for when I lose them.

(2) There are a lot of possible causes of this , unfortunately. Vacuum leak or exhaust leak are the most common. The sensor reading is not matching the air reading from the mass airflow sensor. Can also be a problem in the wiring to the O2 sensors, or with the fuel pressure regulator. Inspect all of the vacuum lines especially the one to the fuel pressure regulator. Air leaks can be hard to find, if you can't find anything, one option would be to have a shop use a smoke machine on the intake.

kimothyanne · Post by **kimothyanne** » 20 Jul 2015, 17:34

Thank you. So far so good on the MAF sensor cleaning (fingers crossed).

Also, it's a relief to know I can go to a hardware store to get the screw as the nearest "imported" type car parts place is many miles away. I'll let y'all know what happens.

As always, I remain grateful to you all.
kimberly