I'd like ANYBODIES opinion on something... I am getting the P1153 sensor 1 bank 2 passenger side forward 02 sensor. I have a 2002 Corvette with 82 K miles and I installed long tubes and am running with 4 cats installed and yes all 4 02s are in their proper location. I sent the headers to Jet Hot and had them ceramic coated inside and out before installing them because I was aware that the 02s that far away from the head would NOT allow them to reach 1200 degrees. And ceramic coating inside and out keeps the heat inside the header tubes. I can touch the headers after only about 3 minuets after shutting the engine off at the collector and at the factory 02 area.

I have ZERO exhaust leaks. I cleaned all Chassis GROUND locations and even installed 2 additional aftermarket strap grounds for good measure. And I used zero anti seize on the threads. I also switched all 4 02s with band new ones TWICE! And the P1153 keeps turning on after 2 or 3 days. So this time I switched the forward passenger 02 with the forward driver 02 and I did NOT even bother cleaning it just installed them and 3 days later I get P1153 AGAIN! So I know for a FACT it is NOT the 02s. The ONLY thing I can think of is the fact that they are place way too far south of the head and are simply NOT getting HOT enough!

Never had ANY codes prior to the long tube install. I was able to turn the key and it would fire up instantly every time. Now if I try and normally start it, it will crank and crank and not start. So to start it I have to turn the key to the on position and then back off and then to the on position and then it will fire right up. I replaced the fuel pressure regulator thinking fuel would drain back into the fuel tank. That did nothing. I replaced the fuel rail damper with a new one. That did nothing. I preformed a fuel pressure test at the check valve on the fuel rail 62 psi and I did a 30 minute leak down test and only lost 5 psi over 30 minutes.

Once it starts it runs perfect, once it is at running temp I can shut it off and it restarts perfect. I replaced the plugs because they were black from being too rich and it started perfect in the AM for about 1 day (autolite double platinums) I pulled a couple of them and they look like they just came out of the box clean as new after about 225 miles on them. I used a laser thermometer and cold tested the temperature/on bord heaters on the upstream o2s I got 125 on the left bank and only 62 on the right bank and about 44 on the two down stream sensors do you know what the internal heater temp should reach on their own? Also I am aware that on the long tube header the upstream 02s are much further down streamI had to extend the wires about 18 inches with solder and heat shrink.

So my other question is do ANY OF YOU have any knowledge on relocating the 02s by welding up a bung in the #7 and #8 primary tube further up closer to the head (factory location on the old cast manifolds ) So I don't have to use wire extensions and so I can avoid spending a bunch of money on the other option (tuning) and STILL have the 02s too far down stream with the code simply shut off?

I also realize that if I do the relocation I will NOT be getting the average reading from all 4 cylinder off each head but only a reading off the single #7 and #8 primary tubes. What would that hurt? How big is the possibility of burning a hole on my pistons from an undetected lean condition from not sampling from all 4 cylinders per side only the two #7 and #8?

 

I don't think your problem is the o2 sensor being too far downstream, plenty of people run them in that location using longtubes without issue. It also sounds like the heater circuit for the bank 2 sensor 1 isn't working giving you your colder temp reading, however it's interesting you aren't seeing a heater circuit code as well. To me it sounds like a failed sensor, computer isn't getting the correct information causing the rich condition. The sensors can be delicate, pretty easy to "kill" one just by removing and replacing during the header install. I've done that myself on 2 occasions. They are also sensitive to penetrating oils and other fluids.

A good test would be to swap bank 1 and 2 primary (1) sensors. If your code switches to bank 1, you know the sensor has failed. If the code doesn't switch then of course you have a different issue, but that being pretty easy to do it's where I start.