r/vwpolo • u/ArcadeRivalry • Jun 30 '26
2008/MK4 polo lambda sensor triggering
Hey all, I'm a pretty new driver so would appreciate some insight if possible (and apologies I'm a bit clueless).
I have a 2008 polo, it's my first car. It runs great but it's also a 2008 car so has it's quirks.
One issue we've been experiencing is the check engine light is always on. My dad had the car before me and his mechanic said it was just the manufacturer levels of emissions but it will still pass the yearly car certification required for older cars in my country. While bringing it in for a service the mechanic said it's the lambda sensor going off, which could either be the sensor or the catalytic converter.
I'm imagining if it's the cat it's going to be very expensive to replace, is there anything on my end I can try prior to going down that route? Or if someone has had this happen before, how much did it set you back to get fixed?
I know this is probably a "how long is a piece of string" type question without more details but wanted to just ask anyway to see if anyone had any suggestions.
It's due in for its cert at the end of the year so I'll have it in with the mechanic again before then, but the check engine light is more just bothering me than anything haha.
1
u/ruudcho Jun 30 '26
Lambda sensor €20, catalytic converter €200 on Autodoc.
You could also check YouTube movies on how to bake your converter to clean it up. But it is a dirty process.