Emission control removal

[CountryBoi]

I have a 1/2ton 1986 gmc 6.2L, and I want to remove the egr and epr valves for more power, Am I crazy? If not how do i do this? I know the valves are wired in the fuel pump and I dont want to screw this up.

[john8662]

Hey Country Boi!

Yeah, it's a pretty common upgrade, with some real benefits.

Option 1:

Disable it from functioning, just remove vacuum to the solenoids on the driver's side rear head. This just prevents the EGR from opening, and prevents the EPR flap from closing.

Option 2:

Removal and replacement with other parts.

Replace the intake manifold with the appropriate year intake off a "J" series 6.2L, this rids the truck of EGR (better flowing intake too).

Remove the EPR, remove the studs that hold it to the manifold on the driver's side, then replace the studs with the correct length studs, you can probably just push your exhaust pipe upwards to reconnect it to the manifold with the new donut, using same hardware (springs, nuts).

Sounds easier than it is...

The intake replacement and EPR disable is usually the standard upgrade.

[DmaxMaverick]

If you have pipe clearance issues with the EPR removed (I did), it can be left in place with a very simple modification. Knock out the butterfly and pull the shaft. Insert short carriage bolts (1/4 - 3/8" X 1.5"??) from the inside, just long enough to get a lock washer and nut on the outside. Or, you could weld the holes closed. It's only restrictive if the butterfly/shaft is left in.

[CountryBoi]

thanks
guys, but would it screw anything up if I pull the wires on the solenoids and fuel pump?

[DmaxMaverick]

The 86 model isn't electronically controlled, and the emission system is passive. You can unplug/remove the solenoids, or leave them plugged in. It won't change the way the engine runs (minus the smog stuff operation). There should be 3 (or 2) electrical connections to the pump: FSS/ESS (Fuel/Engine Stop Solenoid), HPCA (Housing Pressure Cold Advance), and the TPS (Throttle Position Switch, for TCC lockup if you have the TH700R4, or a vacuum switch if you have a TH400). If you have a "Check Engine" lamp that shows up, you can either cover it, or pull the bulb. If it monitors (some did, some didn't, don't know why....), that is all it monitors.

If you aren't changing the hardware yet (manifold and EPR replacement or modification), you can just remove or block the vacuum lines. You have several progressive options, and they don't all have to be done at once. Unfortunately, you can't eliminate the vacuum system completely, as it's needed for the HVAC system.

[CountryBoi]

Thanks im tryin to remove it altogether, I dont want anything restricting my power until I can aford a turbo