1996 Toyota Tacoma has black smoke from tailpipe and check engine light on.

Hi. I have a 1996 Toyota Tacoma which will not pass the smog check. When the engine is first started and idling, the check engine light is off. When the engine warms up to operating temperature, the check engine turns on and it starts pushing black smoke (carbon) from the tailpipe.

Then few minutes later, the check engine light turns off and then on again. I check the EGR vacuum switching valve (vsv) and it's kind of heating up on the EGR side. I check the EVAP canister vacuum switching valve and it seems to be working fine (pulsing about three time every second). When the check engine light is off there is no carbon black smoke coming out of the exhaust. When the light turns on the black smoke starts. Thanks for you help.