"The P0159 code is set when the Engine Control Module (ECM) detects that the rear O2 sensor takes more time to respond between rich and lean than the specified time."
O2 sensors do slow down over time, but see you only have 41K on this thing. EPA just had to add this sensor so we can get another code. Use to hang on a voltmeter on these things to get at least 6-7 pulses per minute. Good question if oxygen leaks into exhaust, usually under positive pressure. Since these things get hot, dang hot, could be wire connection problems.
So , Nick . . I have a new NTK sensor the recommended O.E. one should I bite the bullet and put it in and clear the code and drive it ?
But the million dollar question is which is it ? I'm thinking it's the last one i see ? this thing has 3 cats, 1 in each at the engine and 1 in the y pipe .. the 3rd cat is after the y pipe , and there is none past the y pipe. Thanks !
I question why you are throwing an O2 sensor at it if the dealer's best guess is an exhaust leak. However, if you have already spent the money for a new one there isn't much to lose by the parts-swap.
This will be a sensor after a cat (the end away from the engine). Pick one and disconnect the cable to it, then see what sensor "codes" from the cable being disconnected. Not the B2S2? Then pick another to try.
Not too many people are aware of the EPA emissions warranty, I knew about it a long time ago and received a free EGR valve from my dealer with a 200 buck price tag. But it only good for eight years or 80,000 miles, same BS as whichever comes first.
Read you only have 41K miles on this thing, but 12 years old, so out of your pocket book comes the cash.
Use to be a 15 buck item, but somebody told the EPA that they are worthless until they warmed up, so added a piece of nichrome wire to warm it up a little quick, but the engine thermostat was still cold so it couldn't take over until the ECU switched over to closed loop mode. What it did do what more than double the price of these things.
Super slow only about 6 switches per minute, so the computer software has to do the averaging, what they do is design the software to do the averaging, if they detect a bid of oxygen increase the dwell time of the injectors to enrich the gas to burn that oxygen.
Before all this stuff, still have an air/fuel ratio meter, and would drill the jets for a 14.7:1 AF ratio, so called stoichiometric ratio. But became a major effort when in 1972 catalytic converters became law, had to replace those with a straight pipe do the test, then put the cat back on.
Last vehicle was our 1982 P-30 motorhome, for whatever reason, was not required to have cats. I was able to increase our fuel economy from 10 mpg up to 15 mpg, but that was at 55 mph. It was geared for this speed, anything faster or slower would use more gas.
Wasn't born paranoid but became that way, was living in a small township in Northern Wisconsin where they didn't know the difference between a Model T or that new stuff. But I had to make frequent trips to Chicago, and if somebody hit me and found no cat on my car, would be in for a stiff fine, so I put it back on.
Little more freedom in the sticks, could actually do target practice on my land with a real live gun, legally.