Multiple CEL Codes
 

Greetings all! I am a very happy owner of a recently acquired 97 Boxster with 95k miles on it. The cars runs great but is producing many CEL codes:

P0134 Oxygen Sensor Ahead of Catalytic Converter (Cyl. 1 - 3) - Interruption of Signal
P1123 Oxygen Sensing Adaptation Area 1 (Cyl. 1 - 3) - Lean Threshold
P1125 Oxygen Sensing Adaptation Area 1 (Cyl. 4 - 6) - Lean Threshold
P0410 Secondary Air Injection System - Signal Implausible (Cyl. 1 - 3)
P1115 Oxygen Sensor Heating 1 After Catalytic Converter - Above Upper Limit

I don't know the maintenance history, so after reading through many posts here I am leaning towards having all four 02 sensors replaced. The P0410 code makes me think there is another issue... I think I will try cleaning the MAF sensor and if it returns, have that replaced, too. Thoughts?

-Zack

Looks like wiring issues. Rodent damage or heat damage between your sensors and DME. Give it a look.

OK. I'm going to pop the trunk cover and check the wiring today. Someone else suggested resetting the DME/ECU by disconnecting the battery for 15 mins? About the O2 sensors... If I decide to pull the trigger and replace all four, are they all the same? I've seen them as low as about $80 on eBay but the info seems inconsistent on wether the ahead/behind catalytic converter are the same sensors. Thanx!

Lots of info on O2 sensors here if you do a search but... none of your error codes point to failed sensors. Throwing parts at the problem can be agonizing and expensive.

Understandable. Having read so many raves on here about how much better everyone's cars performed after having the sensors replaced, I figured it would be a good idea regardless. My boxster has had 4 previous owners and 95k miles put on it, and I don't know the maintenance history. I found a good deal on a set of four new Bosch sensors for only $299 so I decided to grab them. Also, I pulled the trunk cover to inspect the ECU and cabling and it's all in perfect condition - doesn't look a day old.