Does anyone know why after a long drive (over 200 miles) on freeway speed, check engine light appears on my Volvo C70 and then when I drive for about 2-3 days in city speed limits, the same light dissapears?
I have noticed that this issue is becoming more often (it used to show up when I drove more than 400 miles on freeway speed).
Any info will be helpful!

 

What is the code reading?

 

the code reading for volvo C70 is P2177

 

P2177, it means that there is too much oxygen in bank 1 of the exhaust. Bank 1 is the back of the engine on a front wheel drive vehicle, it is the passenger side on a rear wheel drive vehicle. you can search for a leak by spraying down the intake manifold with carburetor cleaner while the engine is running. when the idle changes or the engine runs rough, you found your leak.