I have a 93 Vert that usually runs liked a raped ape. It has a DRM modded 383 with all of the bells and whistles. Has 43k miles on it, replaced the Opti, cap, plugs, wires, IAC valve, fuel filter all within the last few thousand miles.

Recently driving to work and started to sputter like it was out of gas. Pulled into gas station and topped it off thinking maybe my gas gauge was broke (showing 1/2 tank). Topped it off, took 13 gallons, gas guage was OK. Car fired up went to work without a sputter. Went to leave at lunch a few hours later and it fired and stalled. It would start up for 10-15 seconds and run like crap and eventually stall. Let it sit for 10-15 minutes tried again and it started and ran perfect, took her home without any problems. Checked for codes, nothing. Thought maybe I had some bad gas or vapor in the lines. Took it for a drive around the neighborhood for 10-15 minutes no problems. Thought it must have been a fluke. Started for work again yesterday, got to the same exact spot as last time and it started to sputter and die on me. U-turned got her home without dying. Runs like it is not getting enough fuel or not running on all cylinders , no codes stored though. Fired it up this morning and it ran fine again cold, once it warmed up it started to sputtter again, listening to the exhaust from behind it seemed to only be sputtering so much from the drivers side. The drivers side exhaust is also a lot hotter to the touch than the passenger side.

My exhaust is modded with short tube headers, stock cats, straight pipes with no resonator and borla mufflers.

Does this sound like a clogged cat, or should I be looking for something else like a TPS or EGR valve? I have a helms manual which is great but with no tech-1 or scan tool and no codes stored I am a little stumped. Sorry such a long post but wanted to give as much info as possible.

 

Sort of sounds like a problem with the spark plug wires, likely on the driver side since you mentioned that is the exhaust tip where you can hear it most. When you put the new wires, on did you use wire protectors where they squeeze through between the accessories mounting bracket and the power steering pump plumbing? Because the tend to be in direct contact with the the bracket and plumbing there. Without wire sleeves (protectors) engine vibration might cause enough weakening of the wire insulator on each wire for 1,3,5,7 cyl's or any of them, to cause one or more to arc to ground right there once the engine gets up to operating temp and things get hot. Arcing problem with plug wire(s) often will not show up until the engine gets hot. I had a bad plug boot on the #1 cyl's wire that was acring to the exhaust manifold heat shield. Just that alone made it feel like it was going to stall when it started doing it and the car would be in gear (auto trans) stopped at a traffic light, it really shook and bucked.

On the other hand it could be the EGR valve sticking open. EGR opens up around 2000rpm I think and if the valve were to remain open when rpm's drop it would make it run progressively more ragged as the rpm's approach idle speed. Take your fingers and slightly pull open your EGR valve some time with the engine idling and you'll see what I mean.