TensorWorl

I am 100% sure someone has asked this question and gotten an answer but my google skills are apparently terrible. I am looking for a schematic/picture/diy of how to replace the EGR Valve on an 03 GS300. I understand getting flamed for this but I've seriously done every search I can think of both on google and in club lexus search. I can find the EGR for the SC300 and first gen GS300 but neither look like my engine so I am assuming it's different. Sorry and thank you.

FrankT

took care of that crap with VVTi
So no EGR on your 03 GS, there you go.

...so what the heck is wrong with your car?

TensorWorl

:O That was not the response I was expecting. I was getting codes P0401 and P0402 which are EGR related codes and I figured it needed to be cleaned since it has 185k miles. It was happening like once every 2 or 3 months and there was hesitation at acceleration from idle. In the last 2 days it has started idling rough and pulling new codes. p0171 and p0174 cylinder bank lean. I figured this was related to a leak at idle that was causing the ECU to pull a lot of fuel trim. I didn't think the two were related so I was going to fix the EGR and then see what I could find about leaks at idle. Now I am altogether confused.

TensorWorl

I was able to figure out what the issue was. The resonance box between the MAF sensor and throttle body was leaking as the bottom had started to fall off and was only pulled back air tight when I accelerated and the vacuum pulled the bottom of the box up. Weirdest thing I've seen in a while. I can only guess it was doing this l a little at the beginning and for some reason the ECU decided that was a tell tale sign that the EGR system was leaking despite no EGR in the car. Now that it's fixed I figured I'd post the fix in case someone else one day has an issue with this. I am also posting a pic of the box from another CL post.