Ok,I have the po402 code and I've been reading about cleaning the throttle body ports,etc.I was wondering if it is possible to use a guitar string to slide into the ports vs. removing the throttle body to clean the ports.Would this work? Anyone try it?

 

Not possible, let alone not adviseable. The carbon that is built up will more than likely cause damage to the engine if it gets into the intake manifold. Removing the throttle body and intake elbow is the safest way to do it. Carbon is very hard, and having chunks of it fall into the manifold is a no-no.

 

I just remove the throttle body and wipe away the carbon residue at the ports. Then I put in a fairly large rag into the intake elbo to catch the carbon coming out of the ports during the next step.

I then take off the EGR valve and shoot carb cleaner into the port liberally. Let of soak for a while and shoot it out with compressed air. Repeat a few more times...

It's just my humble opinion, but if you have over 50K miles on the vehicle, I'd just go ahead and replace the EGR valve and DPFE sensor while I was in there. If you don't replace the EGR valve, at least put a new gaskette on it and put anti-seize compound on the bolts.