I have the 95 chevy lumina 3.4 V6, that we just put new timing belt, (2) new idiler pullys & new Tensenior pully on. Now when driving and when you reach 4000 rpm'* it craps out & sputters. Also the car would not pass smog due to the (PPM) being very high. I have never had any issues with smog before. Can anyone help me?
Thanks

Welcome to the forum, Jerri. I've moved this post into the Chevy Mechanical & Maintenance section, where the gearheads live. You should get an answer soon.

How was the vehicle running before the timing belt was replaced. Did it break, preventitive maintenance? Was it doing the same thing and you thought that was?

Is the 4k RPM a hard and fast rule? If you held it in a gear, does it pull strong until 4k rpm, and hit the wall? Any Service Engine Soon light?

The car was running good, Yes the belt broke & shredded, we did some preventive maint, It was doing the sputtering thing before the belt issue, sorry for my confusion on this but what does the hard & fast rule mean?) and yes if you hold it in gear it pulls strong then hits, No on the engine light, this has not come on.
Thanks

Does it sputter, or does it feel like it is hitting a limiter?

Hard and fast would be it happens at 4k rpm no matter what, where as if you do something different, it changes what rpm it happens at.