Exhaust Smoke

[quote:521725e067="Becky2275"]Nissan Sentra 1996 188,000 miles. 4 cyl. When driving in town or idling. Car will slow down as if its going to die and then it emits alot of gray smoke. Its getting to be more smoke as time goes on. I clouded up a whole block this weekend. The embarrasment sent me home with it until I can figure out the problem. It has been hooked up to a computer everything was fine. I also had another mechanic drive it but it smokes randomly so he didn't see it. Highway driving no problems. Just driving very slow or after a long idle when it feels like it. Could it be the cadillac converter?[/quote:521725e067]

Could be a restricted exhaust or the EGR is acting up. and also fuel pressure problem.

[quote:f99fcaa53f="Becky2275"]Nissan Sentra 1996 188,000 miles. 4 cyl. When driving in town or idling. Car will slow down as if its going to die and then it emits alot of gray smoke. Its getting to be more smoke as time goes on. I clouded up a whole block this weekend. The embarrasment sent me home with it until I can figure out the problem. It has been hooked up to a computer everything was fine. I also had another mechanic drive it but it smokes randomly so he didn't see it. Highway driving no problems. Just driving very slow or after a long idle when it feels like it. Could it be the cadillac converter?[/quote:f99fcaa53f]

You might also want to check your oxygen sensors as well as the catalytic converter and your gas-air mixture as well. Grey smoke is usually a rich mixture smoke, however the amount you described doesn't seem to fit that as much as an exhaust or oxygen sensor problem. But its still good to check.

Currently I have a 96 Maxima with 140k miles that emits white smoke. Which is most likely the head gasket.

Joe