My SES light went on driving on the highway the other week in my 98 WS6...I took it to autozone and a p0102 came up- Mass Air Flow sensor-low input.

The car feels a little down on power(unlesss I'm just used to it now) but idles and starts up the same. I installed a used screened MAS from a 00 TA I bought from a member here who assured me it was good, with no difference...I cleaned all the wires around and MAP sensor with MAF cleaner with also no luck...so I either have 2 bad MAF's or 2 good ones and another problem...what to do?

My original MAS was descreened when I got the car about a month ago...I cleaned it with contact cleaner then and cut my airbox out and bypassed the t-body coolant...it also has an MTI lid.

 

my only other option at the moment is to buy a brand new MAS from an auto parts store and try to return it.

 

Check the Eng Sens fuse under the hood.

 

which one is that? I gave all the fuses a quick once over and all look ok but it just got dark....I'll check more thorough tomorrow. I foud this link about the code
http://gearchatter.com/viewtopic8767...d10ca157025827

and I really should have followed some of those steps before buying another MAS but when the clerk at autozone did the diagnostic and assured me it was a "bad sensor" I didnt think it could be something else.

 

I didnt think they were related but I'm also getting a "4th gear slippage" code 1870 I think. The member I bought the maf from said his friend was getting the same codes and it turned out to be burnt wires by the transmission that controls both circuits...I looked and couldnt find these wires...anyone know whick ones exactly they are?

 

Did you doublecheck the ENG SEN fuse? The MAF, 02's and reverse lockout are on the same circuit - maybe that's the burnt wires by the trans he was talking about? P1870 is transmission component slipping and a most likely a separate issue.

 

I dont know exactly which one that is my front fuse box is missing the cover but I check all of them and all good. I had no SES light before than both codes popped up.

 

There's a diagram in the owners manual - if you need one you can look at/download one at http://shbox.com/pdf/manuals.html Pull the fuse and check it with a meter, sometimes it's hard to tell if they're bad - or replace it with a new one. Burnt/arcing wire should pop the fuse.

 

The two times I have seen this code it was caused by a bad MAP sensor. You need to scan the car and see if the MAP sensor is switching properly. Another good test is to see if the car will run smoothly without the airflow sensor. If the MAP sensor is working the car should run w/o the MAF, and if it is not working the car will run poorly or not at all.

 

I checked all the fuses and cleaned the area with MAF cleaner(might as well get my $6 use out of it) I swapped the 20 amp ENG SEN fuse with another one and disconnected the battery...Light is still on.

It's a possibility but both the transmission code and the maf code appeared at the same time,(there were no codes when I got the car) I dont think a bad MAP sensor will trigger a trans code which leads me to believe like was mentioned its the same circuit somewhere.

 

Service manual and a digital meter.

 

I have a manual-no help.

What will I test the voltage on?

I've checked for any burnt wires underneath-nothing, I've checked all fuses-ok, I changed MAS(although with a used one)-light is still on and gas mileage and performance is still down!

 

Did you follow the diagnostic table in the service manual?
It is a MAF by the way. Mass Air Flow (MAF) sensor.

Go to:http://gearchatter.com/viewtopic8767...fb72339e10c415 and follow the steps and see what you find.

 

I'm goint to try and test voltage tomorrow, I found this thread about the maf and transmission code being related my car all of a sudden seemed to be shifting harder normal driving from 1-2.
https://ls1tech.com/forums/automatic...1-2-gears.html

 

Well I couldn't find my voltmeter...looks like I'll have to take it to somebody!

Anyone know of any good LS1 diagnostic mechanics in the central FL area?

 

Taking it to a dyno tune shop probably wednesday...I also tried a brand new maf and disconnected battery...light stayed on I also tried disconnecting maf...runs just as smooth and good.

 

I took it to dyno tune place for a complete engine diagnostic...the problem according to the tech is the torque converter not engageing...and causing the p1870 code and perhaps the p102 code. The MaF sensor(s) are perfcetly fine...so I guess I'llbe taking it to a trans shop soon.