O2 Sensors

[cvhs18472]

I just got a CEL on my 98 Base/Tip with 41K. The P codes are 1124 & 1126 with fault codes of 27 & 36. I replaced the MAF sensor about 5K ago. Is it time to replace the O2 sensors or is it something else? Thanks in advance for your consideration. Ed

[1999Porsche911]

I just got a CEL on my 98 Base/Tip with 41K. The P codes are 1124 & 1126 with fault codes of 27 & 36. I replaced the MAF sensor about 5K ago. Is it time to replace the O2 sensors or is it something else? Thanks in advance for your consideration. Ed

The O2 sensors are simply reporting that your engine is running too lean. You wouldn't replace your smoke detecter in your house just because it went off because of a fire, would you?

Check for leaks in the intake system, including vacuum lines and throttlebody connections. Make sure your oil filler cap is sealed properly. Are you running the stock air filter?

Edited July 12, 2007 by 1999Porsche911

[cvhs18472]

I just got a CEL on my 98 Base/Tip with 41K. The P codes are 1124 & 1126 with fault codes of 27 & 36. I replaced the MAF sensor about 5K ago. Is it time to replace the O2 sensors or is it something else? Thanks in advance for your consideration. Ed

The O2 sensors are simply reporting that your engine is running too lean. You wouldn't replace your smoke detecter in your house just because it went off because of a fire, would you?

Check for leaks in the intake system, including vacuum lines and throttlebody connections. Make sure your oil filler cap is sealed properly. Are you running the stock air filter?

According to the fault codes it is a Type 4 Short to B+/above upper limit/rich mixture threshold. This seems to not be a lean problem. Maybe it is. I checked the oil fill cap and all is well. I am running a stock air filter. Is there any good starting place on the vacuum system? Thanks, Ed

[1999Porsche911]

I just got a CEL on my 98 Base/Tip with 41K. The P codes are 1124 & 1126 with fault codes of 27 & 36. I replaced the MAF sensor about 5K ago. Is it time to replace the O2 sensors or is it something else? Thanks in advance for your consideration. Ed

The O2 sensors are simply reporting that your engine is running too lean. You wouldn't replace your smoke detecter in your house just because it went off because of a fire, would you?

Check for leaks in the intake system, including vacuum lines and throttlebody connections. Make sure your oil filler cap is sealed properly. Are you running the stock air filter?

According to the fault codes it is a Type 4 Short to B+/above upper limit/rich mixture threshold. This seems to not be a lean problem. Maybe it is. I checked the oil fill cap and all is well. I am running a stock air filter. Is there any good starting place on the vacuum system? Thanks, Ed

The code definately indicates a LEAN mixture passing by the sensors. Because it is BOTH sensors, it is unlikely (but still possible) that it is fuel injectors, plugs or exhaust because the problem is with both banks on the engine. Having a scanner that shows various sensor readings would make the job easier. It could be a dirty MAF. fuel pressure problems, fuel pump problem, or anything that will either reduce the amount of fuel to the engine or anything that will increase the air to the engine after it has been measured by the MAF, such as an intake leak or vacuum line leak or a leaking oil seperator.

Before I did anything, I would eliminate it being a fluke and reset the codes by disconnecting the battery for a few minutes. (make sure you have your radio code). Throw in some fuel injector cleaner and run through a tank of gas and see if the codes come back. Make sure your idle control valve and throttlebody are cleaned.

Edited July 12, 2007 by 1999Porsche911