EGR Valve?
 

I've tried searching but does anyone know where the EGR Valve is located on a 2003 Blazer?

if its the same motor as mine is in the 98. should be in the center of the engine on top between alternator and ac compressor, more towards the front. yea my descriptions suck sorry.

Nope, mid-02 and up do not have an EGR valve. GM redesigned the 4.3L and introduced it in the middle of the 2002 production run. The fuel injection spider, EGR system, knock sensor type, and a few other "refinements" were made at that time.

Soo it's right by the flux capacitor??

And the muffler bearings and halogen blinker fluid!

So she doesn't have one at all? I got all the symptoms of a bad EGR Valve... poor gas mileage, light knock, and an engine code for an evap leak that doesn't exist. I've replace the PCV Valve, fuel filter, and had it hooked up to a smoke machine to check the hoses. I don't know what else to do. To make matters worst I'm stationed in Germany so I can't go to Auto Zone to get the codes run it cost about $20 every time. Any ideas on what I should do?

I sucked up and paid for the engine scan P0455 Large Evap System Leak. The thing that trips me out is I've had a smoke machine hooked up to the system twice and I've sprayed all the lines with carb cleaner. I'm pretty sure I don't have a leak. I think I might break down and take it to a mechanic. This is really starting to get on my nerves.

When you had the smoke machine on it, did you also have a scan tool capable of opening and closing the related solenoids in the system to verify that they were working? Did you check the engine for smoke in the intake that would result from a malfunctioning EVAP purge solenoid? If the purge solenoid were stuck open, then it could act similar to a failed or failing EGR valve.

I took it somewhere in the states before I came here and they ran the smoke test. They said they couldn't find anything wrong with it and told me it was most likely my gas cap. I replaced it and there was no change. I didn't have time to get it rechecked by another mechanic before I left. I asked a friend today and they said the only person around here that can do a diagnostic check on the evap system charges 90 euro ($120) an hour. This is going to suck. Are there any things I can do before I take it somewhere?

I think I might have fixed the Blazer on a whim. I was thinking the most likely cause for the code would be the gas cap. I ordered a new one but it's going to take atleast 2 weeks for it to get here. So today I had a whim and put vaseline on the O-ring around the gas cap. I disconnected the negative battery cable and waited. I've put about 50 miles on her and started her about 4-5 times and the light hasn't come on yet. The knock isn't as noticeable anymore... I know it sounds weird but has anyone else used this as a temp fix or done anything like this?