I cut off my stock muffler and 1500 miles later truck has a very rough idle almost like I put in bad gas but that is not the case what could be the cause of this??
I have a 2000 silverado ext 283 V8 just turn 100,000 miles
I would guess that the PCM (powertrain control module) can't compensate for the decreased back pressure. Are you getting any OBDII codes? I believe your 2000 Silverado uses a multistage EGR valve that works in part by monitoring the exhaust back pressure. It could be the source of the problem. You might also want to try reseting the PCM by disconnecting the battery to clear the memory and have it re-scan the trucks new operating characteristics.
In the 1990’s, electronic (digital) EGR valves
began to replace vacuum-actuated EGR valves
because they can respond much faster to changes
in operating conditions and work independent
of intake vacuum. Several different types
• Single-stage (A single solenoid is used to open
the exhaust passageway valve). The computer
monitors various sensor inputs to determine
when EGR is needed, then cycles the EGR valve
solenoid on and off to control the amount of
exhaust gas recirculation.
• Multi-stage (Used on various late-model
General Motors applications, this type has two
or three solenoids that open separate exhaust
passageway valves. See Figure B.) With this
setup, the computer uses a step strategy to
increase EGR in stages. If only a little EGR is
needed, one solenoid is energized. As more EGR
is needed, the second and third solenoids are
energized. On the three-solenoid applications,
up to seven different combinations may be used
to control EGR flow.
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