It will also cause the tb to stick, gum up. I have mine deleted with a tune in my 99, I get around 20mpg. Delete it an tune it, its junk!

 

My TB was all gummed up and I don't have EGR. I think the gumming up of TBs and intake manifolds is more related to the crappy PCV system. I wonder if it would be much better with a good catch can.

 

That's a maintenance issue there, and a PCV design issue. It's a combo of the PCV allowing much oil into the IM and the carbon particulate from the EGR getting stuck to it when the pintle on the EGR valve allows gas through.

PCV system is the more likely case for TB being gummed up, as the Fresh air side of the PCV (which often times goes dirty) is at the front side of the throttle blade right next to the IAC port.

EGR has it's place, and in Physics/Thermodynamics it works. AS such, it works in our engines, since they obey those laws as well. You can tune an EGR equipped engine to get mileage that would best a non EGR equipped engine.

GM found out a way to "Meet" EPA/CARB/CAFE emmisions/mpg guidlines without EGR. That doesn't necessarily mean that it is the optimum solution for MPG numbers, it just means GM was able to produce trucks that met the mandated requirements with less parts and expense on their end. Higher Profit for them in doing so. See how that works?

And yes, you do have to tend to the maintenance items on these trucks to ensure they run factory fresh, not just oil changes and air filter change outs.

 

this thread reminded me of this, thought i'd share

 

Pretty much all throttle bodies get gummed up with carbon, as mentioned, it's a maintenance concern that should be addressed every 12 to 15k or once a year, whichever comes first.

 

Pretty much all dry flow throttle bodies do but with throttle body injection its self cleaning.

EGR basically mimics the benefits of having a cam with a lot of overlap but still gives you that ultra smooth stock idle and low power that the auto makers think we want. By recirculating the burnt exhaust back in you dillute down the amount of oxygen rich air in the air fuel mixture which in turn makes it less likely to detonate. As a result you can run much more timing therefor increasing the part throttle power and fuel economy. Another way of looking at it is like running 93 octane with maximizing your timing at cruise vs 87 octane and limited timing so it doesn't detonate. I had been running the 02 operating system on my 99 for several months with the EGR turned off and got a consistant 14-15.5 mpg. I just recently turned it back on using the stock 01 EGR settings and I haven't gotten a full highway only tank ran through it but so far it seems to be helping. It runs freer, runs smoother, quieter, and with less pedal. IMO if utilized properly EGR can be pretty beneficial with a stock or very mild cam.

 

please report back with mileage results.

Wonder if there is any way to add an EGR to an 03?

 

Sorry, I was referring to port injection only, should have specified

Looking forward to your results with the EGR turned back on...I removed mine also when I swapped in an 02 PCM, but I've always seemed to get 14.5mpg, before and after cam, tuning, headers, etc. Haven't logged mileage since the new trans and converter though.

I've fixed many older vehicle's pinging problems by replacing EGR valves or cleaning EGR passages...my old 85 MonteSS had a pinging issue when I had the original 305 in it that was cured with a new EGR valve

 

Not too eventful. I finally got this last tanked burned through and filled up and got a true 15 mpg. Not horrible considering all the wind and the short trips around town and idle time. I do feel like its improved somewhat but not too drastically yet. I have to go to the Tulsa area at the end of the month for some training and to Dallas sometime in October and plan on driving it both times. Hopefully I can get some real numbers and see what its able to do.