i have a 98 s70 (automatic) volvo and sometimes whenever i stop at a red light or a stop sign, the RPM will start going between 900 to 200 and will just start jumping around like crazy and black smoke pours out of my exhaust whenever i try to give it any gas when this happens, and usually the engine ends up cutting off on me and i have to restart it a few times

sometimes, whenever i hit a red light or a stop sign, the cars engine just cuts off completely and once again, i have to restart it.

i just replaced the coil and got new spark plugs.

any idea what it could be?

 

also, i hooked it up to a computer and it threw a code about one of the o2 censors i think. it said something about the system being too lean.

i apologize for my incoherent understanding, im not very car savvy

 

also, it hasn't thrown any codes since the mechanic i took it too reset it after he saw the o2 censor code and everything.

 

I would say bad O2 sensor or Mass Flow sensor.

 

anyway to test either one without having to order new parts?

 

Not really unless you had a scanner that reads real time to make sure they are moving.

 

i got a mechanic buddy coming over tomorrow or the next day

i'll have him hook it up to the computer once more

thanks mate

 

I'd say MAF over O2 but thats just a guess.

 

Hi clarkcassidy


I have a similar problem as you mentioned and I am still looking for a solution. Have you solved your’s yet?
https://volvoforums.com/m_83268/tm.htm