Here's the deal. Cattman exhaust installed nearly 6 months ago. Headers, high-flow cat, cat-back. Included at the time was an O2 simulator (not from Cattman). Everything went on beautifully, thanks to Jeff.

Over the last 4 weeks, I've had recurring instances of the P0138 and P0158 codes (always together, never one or the other alone), which indicate faults in the downstream O2 sensors. Those are the ones being simulated, as the sensor holes in the catback are plugged. Has anyone ever seen an O2 simulator go bad? Could the problem be anything BUT the simulator?

Thanks in advance.

 

it could be the simulator...basically this code means your downstream o2 sensors are reading a HIGHER voltage than stock....stock reads anywhere between 0 volt (leaner conditions) to 1 volt (richer conditions)....so basically this code means your reading HIGHER than 1 volt...which is out of range...and will throw this code...

the ecu will throw this code if there is a short circuit somewhere....or the o2 sensor is actually bad itself...

 

I have the exact same problem, same codes and everything. Been meaning to get with O2simulator.com and have them send me a new one. Been popping the codes for months now. There is a thread in the All Motor forum about simulating the heater circuit so you can completely remove the O2 sensors, no real solutiuon yet.

 

Thanks for the feedback, guys. Looks like the first option is to replace the simulator. I'll let you know how it works out.

 

Just to update. I ordered a new simulator, actually got ready to replace it, but found my soldering iron was burned out. I had to tape everything back up - thankfully I hadn't cut any wires yet. I cleared the codes again, waited about 4 days and took it in for inspection (a garage, not the DMV), and it passed. I haven't thrown a code again in the 10 days since.

Apparently, either heat, or wire stress, or something along those lines was causing the problem. I'll be hanging onto the spare simulator just in case, though.

 

Did they send you a new one for free?

 

Honestly, I didn't even ask. The company seems to be a one-man operation, and for what they cost, it didn't even seem worth it.

I will add that now that I opened my big f*#$ing mouth about the problem disappearing, it's back. I've got 2 years until my next inspection is due - sometime between now and then I'll replace the sim and hopefully solve the problem.

I'll let you guys know if/when it happens.

 

it may be a frayed wire somewhere on the sim. look for loose strands where the wire connects to the sim body, or the plug on the other end. i have seen happen with computer power supplies, and cd/hard drive connectors.

 

I had a dual output O2 simulator for my headers and after months of trying to track down the cause I finally just extended the downstream O2 wires and had 2 bungs welded in the B pipe after the main cat.
This is the ONLY way you are going to get rid of the stupid codes and CEL.

I spent $10 on the 2 bungs shipped from ebay, $10 for a 1" hole saw and drilled the holes myself and $10 on 25ft of 4 conductor multistranded shielded wire, you must cut this in half, one length for each O2 wire extension and solder everything up. The wires actually are zip tied in the fuel and brake line carrier brackets, its perfect because of our returnless fuel system there is an extra notch that works perfectly. You can sort of see the O2 in the b pipe after the resonator in the pics.

Then I just paid the muffler shop $30 to weld them in.
Hooked everything up cleared the codes and bye bye CEL forever!
This was the best $60 I have ever spent and the car seems to run better with having the downstream O2s getting a proper exhaust signal.

 

I am having the same code bank2 sensor 2, my car is cali. spec. so next to the radiator it would be the one with the red wire in it. correct? Great pic. Allgo.

 

I may very well do that, since the Cattman Gen 2 has the O2 sensor holes pre-drilled. They're plugged now, and the only reason I used the sim was to eliminate potential codes from bad sensors and because the wires were simply too short.

 

wait a second, are those sfcs i am seeing on your car???

 

mocomax,
I assume you mean the cattman bpipe has the bungs because if they are in the headers that is not going to help with your cels.

chronos,
Yes they are the latest, stage I & II from WSPD. I must say they are fantastic and make the car feel 100% stiffer and more stable. I can't stand a sloppy feeling car. With the maxspeeds with illuminas @ 2/2, addco rsb, 225/50/17 turanza lsv's and a decent fstb, the combination of ride quality and handling is matched by few cars I have riden in.
They are really the only reason I haven't sold the car and upgraded to a later model lexus or european brand.

 

I have the same problem with my car but the car is totally stock. The code read P013 "Bank 1 sensor 2". There is a problem with the O2 Sensors.
Can anyone tells me which sensors and where it located?

Thanks in advance.

D