Which one is this on a 98 gt so I can replace it? plz? I also have (2) bank 1 sensor 2 codes as well but i think thats because I have a UPR x-pipe on it . But I also have the updraft bank on sensor bad code.

 

upstream 02 sensors are the ones before your catalytic converters (closer to the exhaust manifolds), and the downstream 02 sensors are the ones farther back in the exhaust system (behind the catalytic converters).

Bank 1 is the driver's side, Bank 2 is the passenger side. Sensor 1 is the upstream sensor, sensor 2 is the downstream.

Ex: B1S1, is the driver's side front sensor......B2S2 is the passenger side rear sensor

 

Bank 1 is the passenger side, Bank 2 the driver's side.



Ford's standard nomenclature is as shown in the diagram HO2S-bn, where b = bank and n = sensor #, the front most sensor being #1.\

OP,

What was the exact upstream code you pulled--it could be a good sensor reporting a problem?

Also, you can make your own MIL eliminators for $5 or so, click here for more...

 

Thanks man ok well here's another one car starts bogging out after about 5 min of driving. Shut the car off turn it back on rightaway and its fine for 5 more min or so. I have 3 chamber flows on it and a upr x pipe no cats. Here the codes and which one would make my car do this.
p0136
p0141
p1131
p1443
Which is thre most improtant and would make my car do this?

 

I should have stated that the bogging out starting up is a reppitive process.

 

You can lookup the codes, along with possible causes and diagnostic tips here.

The P0136 and P0141 codes are both related to the bank 1 (passenger's side) down stream sensor--is it installed and wired up correctly?

P1131 is from the passenger side front sensor's indicating a lean condition that cannot be corrected--often this is from a leak at the X-pipe to manifold flange, the gasket may be bad or the connection loose--this would affect driveability.

P1143 indicates a problem with the EVAP system. This could also affect driveability.

 

I don't know how I got that mixed up LOL. Bank 1 is usually the bank which contains the #1 cylinder which in our case is the passenger side. Duh!!

 

I'd love to be able to tell you I have never had such brain farts, and I find that as I get long in years they are becoming more frequent...