P1131 troubleshooting

[iago]

My 98 was running rough(not the idle but under load or when I really stepped on it) felt like it was missing. Then I got a check engine light. I pulled the code and got:

P1131 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1.

Bank one is the passenger side so when it stops raining I guess I’ll check the plugs on that side, I still have the original plastic intake, so I’m wondering if it could have cracked and caused a vacumm leak? But if so why do I only get the code for one side? Can I get some advice on what to try?

The car has 70K so I guess it could actually be the sensor so this weekend I’ll try switching them from side to side, is this one of those tough jobs? If it’s a pain(hidden, always stuck, knuckle busting) I want to know so I’ll just replace both sides while I’m doing it anyway, but if it’s easy I’d rather not buy parts I don’t need.

Thanks,

Don

 

[sgarlic]

Sounds like the o2 sensor perhaps took a crap on you. It is sort of a knuckle busting job to get those front ones, only because of where the actual connectors are. It can be a little PITA to get up there, but just use a big open end wrench some PB blaster and they'll come right off. Unplug the harness first, so you don't twist the heck out of the wires while loosening the actual sensor.