A few issues that are being a PIA. I seriously apologize if these are ridiculous issues with very simple remedies. I've searched in a million places but, I don't seem to be searching correctly.

2005 g35 Coupe 6mt.

Mod list:
Greddy EVO3 CBE
Berk HFC
Takeda/AFE Intake
Motordyne 5/16" Copper ISO Thermal Plenum Spacer
Stillen Torque damper (thought it looked cool, was a waste. it's now rusted)
Osiris Dyno Tune
Clutch Masters FX300 HDTZ (my favorite replacement ever)
ACT Street light flywheel
Zspeed Aluminum undertray
Zspeed SS clutch line


1) I have Greddy CBE and Berk HFC. I was dyno tuned about 3 years ago and my car didn't throw any codes. Suddenly I'm getting 4 codes, max/min voltage DTC's for both rear o2 sensors. I'm wondering if it really is bad o2 sensors or if I should consider adding extensions. I've seen in a few places that steel wool might help, but, I'm confused because I would assume it would eventually burn out. I know the Berk HFC's have built in extensions so I don't THINK I would need to add extensions to the extensions but it's also weird that it's happening to both sides at the same time.

2) I changed my brakes about a year ago. I had a seized caliper (RR). Okay, figured I would change that and pads and rotors all the way around. Figured I should be fine. Had to go on a road trip recently (~250 miles) and my LR is now grinding with no pad left and my right rear is no longer working at all. It did bed in so I know it was working at one point. After leaving it to sit over night (it rained) and then driving around town. I saw the RR rotor is still rusted, Meaning it's not clamping. I don't understand what would cause this.

3) I'm in a weird situation. I moved back to NY from Ohio and since I have tint and plan on moving back to Ohio soon, I didn't want to register my car in NY so I do drive back occasionally for work/see friends. I have to get an Emissions check by the end of August. However, with no MIL on, my ECM is not ready/doesn't have all the monitors ready. I've completed the SRT drive cycle and reset the computer almost a dozen times for good measure to make sure I am completing it successfully. Still not ready. Decided to drive back to NY because I had to be in the office. Still no CEL, but codes are definitely there when I check against my Bully Dog gauges. (Spent the money on it years ago because I thought it was cool).

I'm at a loss. Confused and very frustrated. My car is starting to fall apart at 144k miles. I've got to change the passenger's window motor soon because of the stupid come down issue and the thermostat because temps bounce around from 188F to 210F just driving around town. I don't need help with those, just the issues listed. Thanks!

I can get the actual codes shortly that are being thrown. Just so mad while I sit in my office at the moment.

 

1. Look it all over for obvious vacuum leaks, use a can of throttle body cleaner and go over Ever. Single. Fitting. and lightly spray, including MAF / Intake tube / Plenum (yeah the entire thing) BOTH PVC valves and the hoses. If you're getting lean on BOTH sensors then you probably are, and it's probably a vacuum leak.

2. Calipers might be fried due to crap brake fluid, this might have been the root issue for the first failure. Take off the caliper, use a C-clamp to squeeze the piston back in, remove the clamp and have someone else LIGHTLY push the brake pedal and ensure your caliper isn't just frozen. Either way have you ever replaced ALL the brake fluid? 144k is quite a bit of use and I'm sure it's trash quality if it's stock fluid.

About that passenger window, do the recalibration on it before you completely replace the motor, as the guides, window seals, motor wears the original window calibration is no longer actually "correct" due to different tolerances on worn components. Recalibrating to what it's ACTUALLY working with now might fix the issue.

If those thermostat readings were from an OBD2 scanner or something it's probably fine, or were you getting different readings before? Does your temp needle on the dash show a higher than normal temp? I'd start with the electric fan and verify it's working properly and that the radiator has no obstructions (like being completely full of dead bees, yeah it happened to me once...), if you're overdue on fluid replacement that could be an issue as well (or be causing something else to build up crud).

Post the codes that are being thrown.

 

Thanks for responding Cleric!

P1146 - Heated Oxygen Sensor 2 Minimum Voltage Monitoring Bank 1
P1166 - Heated Oxygen Sensor 2 Minimum Voltage Monitoring Bank 2
P1147 - Heated Oxygen Sensor 2 Maximum Voltage Monitoring Bank 1
P1167 - Heated Oxygen Sensor 2 Maximum Voltage Monitoring Bank 2

Those are the codes it's putting out. Just got in the house from pulling them again. I apologize. The lean code was an old code my reader had saved from a while back. I thought I had recognized it as one of the new ones. So to go back, I am getting max/min voltages on both rear o2 sensors.

I did replace the brake fluid with Bremsflussigkeit (was on sale at the time, heard it was all the rage) when I had done the brakes last time because I wasn't sure when it was done. I changed them at about 120k miles and bought the car when it had 75k. I'm thinking I might do another flush. The pedal never felt spongy after I was done.

Yeah, the window. I've done the reset including pulling the door apart and trying that way with the reset. It still would come down half way after shutting it. It works fine if I hold it up and then hit the window lock button so I'm not drastically worried about it at the moment.

The thermostat, it's one of the things that I watch for on my Bully Dog gauge so I can see the temperature. It used to ping at 192F all the time very well. I did a flush at 100k miles just to clear out the fluid. On my way to Ohio, I was stopped in 90-degree heat and saw the gauge on my dash fly up and readings at 250F. Luckily, the Bully Dog started beeping like crazy, I pulled off, let it cool down and didn't have any evaporation. Checked the fluid level multiple times after that. Still good. The temp reading just bounces way too much, I figure probably the thermostat. The radiator is clear after pulling off the grill to get a better look. I put power to the fan, to see if it would sputter or lack anything, seemed fine.

 

That's odd to be throwing all 4 codes like that.... I'd check to make sure the downstream O2 sensors aren't both loose and about to fall out or something wonky like that.

 

I thought the same thing. I've cleared the codes before on the ECM and these all come up at the same exact time. Just climbed under the car with a wrench and they are on good and tight. Funny thing is, I haven't reset the ECU since these came on about 200 miles ago and the SES light still isn't on. Ohio E-check is through the OBDII so since it checks the monitors, it's still not going to pass since it's 'not ready'.

 

Can of throttle body cleaner will probably find the vacuum leak then, lightly spray everything that could be sucking air, when you find the spot your rpm's will drop.

 

Can you read live data with your scan tool? I'd start with looking at your short and long term fuel trims for both banks after it goes into closed loop. That will give you an idea if your car is running rich or lean right off the bat. From there I would read the FSM and maybe do some of the continuity checks for the O2 sensors to check them out.

For the rear calipers did you buy reman ones? I've gone through about 4 re mans alone in the past three years on just the rear. It could just be junky parts that you are buying.

I recently put a new fuel pump in my Audi. 20 minutes after driving it down the road it died and I got stranded and why? Because, the company used a crappy plastic hose that blew out, so all the fuel was getting pumped back into the tank.

 

Just went over it for a couple hours. Didn't seem to find any vacuum leaks.

 

Ah, cant read that kind of data. Nothing the the FSM either. The closest things to fuel it looks at is IPW.

When I replaced the caliper a while back, it wasn't it was brand new. I've recently been told that the pin needs a lot more grease than what one might think. I thought I had greased everything well but maybe not. That would suck. I've been there with crappy parts. Especially the Audi. Had an a4 a while back and all the vacuum lines decided to disintegrate all at once.

 

Wellpd, just got home from a round trip of about 30 miles. Now showing only 3 of the original DTC's.


P1146 - Heated Oxygen Sensor 2 Minimum Voltage Monitoring Bank 1
P1166 - Heated Oxygen Sensor 2 Minimum Voltage Monitoring Bank 2
P1147 - Heated Oxygen Sensor 2 Maximum Voltage Monitoring Bank 1

No longer being pushed - P1167 - Heated Oxygen Sensor 2 Maximum Voltage Monitoring Bank 2 -
*I didn't reset the ECM*

 

Once the issues are corrected it will take a while before the computer clears the trouble codes, it's not an instantaneous thing. Maybe in all the troubleshooting you actually fixed the issue?

Possibly also a bad tank of gas...

 

Yeah, I know it does take some time, just found it odd that the one went away. I guess it's possible the issue remedied itself. These codes are somewhat intermittent, however. They always pop up ~100 miles into a road trip going 70+ on the highway. If I leave it alone, it takes a month for them to clear themselves, given I stay away from about 70+mph the entire time. I suppose they'll start to go away since I won't be on any highway for a little bit. Very curious about what would cause them though. The car doesn't and never has run rough.

 

The computer has a lot of leeway for fuel trim, I think the check engine light comes on for lean mix if it has to compensate by +25%. It doesn't mean the engine is ACTUALLY running lean, just that the computer is having to overcompensate for the mix to the point that it needs to be fixed. Could be dirty injectors, bad fuel, low fuel pressure, vacuum leaks, bad MAF, bad tune, etc. Since you can datalog with the Osiris I'd plug it in and try to reproduce the issue, then look the data over (possibly re-e tune) because given all the mods it's likely something is starting to wear out and the computer is having to overcompensate with extra fuel.

 

Sounds like a plan. I'll have to get with my tuner to borrow his Cipher cable then and go from there. Thanks for the help! I'll try to check in later then for those damn issues.

 

I know this is an old thread but its the latest I could find with the P1147 and it involved freeway driving. Were you able to get it resolved? I had it pop on my way from the Dallas area to New Mexico. I forgot to bring my code reader so I bought one in Las Cruces, NM. The guy at the Autozone offered to read it for free but I said I wanted a one of my own to keep in the car in case I need it again. He says its pretty common for them to see codes from people coming there from lower elevations east of there (they are at about 3600' and the Davis mountains I passed through were as high as 4700') because of the change in gas (goes from 93 octane to 91) and elevation and he said once I cleared it the CEL would probably stay off...which it has so far now that I'm in Arizona.