| Author | Message | ||
     Doerman |
The following is just my conjecture and should be taken as such. My anecdotal evidence is this. I had problems with hot starts and rough low rpm (below 4K rpm) running after my check engine light went on at around 1,300 miles. I took it to the dealer and they replaced the front O2 sensor, which was the reason why check engine light came on. It ran and started perfectly after that. Until just recently, when the check engine light came on (10K miles) and it was the front O2 sensor tripping the CEL again. I rode the bike in this condition for a couple of days and noticed the rough running and difficult hot starts. The running problems went away after replacing the sensor and the bike is its smooth usual self again. By the way, when I replaced the O2 sensor I noticed it looked pretty “cooked”. Combining my experience with the fact that O2 sensors are relocated on the MY 09, is it a possibility that people with rough running bikes are riding them with marginal O2 sensor thus causing all kinds of problems? | ||
| Xl1200r |
I would say that is not a bad hypothesis. | ||
| Badlionsfan |
probably why they're moving them further down stream too. | ||
| Bob_thompson |
Quite an excellent point made Asbjorn. Now I'm beginning to think, even though my personal bike is running well, what the cost is of O2 sensors. Maybe I'll decide, based on cost to have at least one on hand at all times. Thanks much for the input. Can anybody with access to a parts manual tell us what they cost? Bob | ||
| Doerman |
The cost is $49.95 (+tax) and the part number is PO277.5AA | ||
| Josh_ |
Wow, flash back to '99 when "everyone" (myself included) was replacing their o2 sensors to improve drivability. Took an ECM update and a new exhaust hanger. | ||
| Doerman |
All this is subjective on my part. But I do believe that the bike runs cooler after the O2 sensor replacement. No two days are the same regarding humidity, temperature and traffic conditions. However in Los Angeles at this time of the year one can actually have close to the same condition several days in a row at this time of the year. I have noticed that the coolant temp is about 5DEG lower with the new sensor in warm ambient and traffic jam condition (grain of salt analogy applies). | ||
| Zac4mac |
Interesting. On my trip to Homecoming, I used some "Rocket Fuel" in Iowa. It says on the packaging "not for vehicles with O2 sensors" but it was the only booster the metric shop had I stopped at. My AFVs are 94.5/99.5 and my rear O2 sensor reads low by .2 Volts compared to the front. Guess it's time to replace the rear sensor. No, I'm gonna wait a while and look at the plugs when I rotate the engine for the third service. The rear plug should be darker. That should be next weekend or the next one... Z | ||
| Bob_thompson |
Zack, it seems as though you have one of the really good running 1125's so I wonder just how much the O2 sensors with that kind of difference in voltage output matters. Also if the rear plug shows its lighter from a good/normal color or just darker then the front still AFV's do however bear out a difference. If its the front that is reading 94.5 wouldn't that denote a slightly "richer" cylinder and IT would be darker? I'm still waiting for the new flash before doing anything really drastic but I really appreciate all your input. Thanks, Bob | ||
| Palerider |
It's funny, I was just talking to my Chevy dealer about my pickup. I was talking about the O2 sensors degrading through use.I asked that instead of waiting for them to go completely bad wouldn't it improve performance if they were replaced when the sensors started to show some degradation of performance? I know not everyone knows all, but he said they either work or they don't. If their performance changes it would set a code. I'm assuming they have a working range, just don't know if you would detect that small change within the range. From what I'm seeing from the posts here that may not be the case. | ||
| Chevycummins |
Palerider, your chevy does have some codes that relate to degradation, insufficient switching code or performance code. It also has a "normal" range that they are tested in and if it falls out of the "normal window" the PCM sets these codes. The "window" may be as big as your picture window on your house, and you probably would not notice a change in the drivability unless they were bad enough to set a code. Its hard to use a scan tool to diagnose the O2 sensors, unless there really slow. On a motorcycle I think that it would be easier to feel a change in the bikes performance from a faulty O2 sensor. You know the performance of the bike better and its lighter so its easier to feel a problem. One thing about the bikes ecm is that if you disconnect both O2 sensor and ride it, you will go a long time before it sets a code. I rode my bike for 2 days with the O2 sensors disconnected and never set a code. It seems to actually run better when disconnected. Go figure! | ||
| D_adams |
I just checked my AFV and I've got 110 on the front and 99.5 on the rear. It runs like crap under 4000 rpm. I've done the TPS reset and just made it learn new AFV values on the way home tonite over a 2 mile stretch in 3rd gear at about 50 mph. When, oh when, will the 09' map come out??? I've also got the $6 Buell solenoid eliminator installed, but haven't physically removed the actuator yet. No codes are showing at this time either. (Message edited by d_adams on August 20, 2008) | ||
| Zac4mac |
I rode around a bit yesterday, got Loretta good and hot and went to "learn mode". She's back where she was pre-reflash, almost exactly. 94.0F/94.5R Hot/not makes a big difference what you get in "learn mode". Z | ||
| D_adams |
I did mine last night at the end of a 25 mile ride. Ambient air temp is about 70 F at midnite here. |
