Another EGR codes problem (PO401, PO402)

Hi fellas, i have a 2002 Mountaineer which check engine light was lit, it has two codes: PO401 and PO402. The local mechanic said that it needs the EGR sensor and they want to charge me quite abit on that...so i want to install it myself but i don't know where the it is located.....anybody know where the sensor is located and how to change it??? and anybody has any luck with their EGR problems.

Then i also experience some sqeuking noise coming from the engine. Upon inspection, the mechanic said that it could be the tension assembly or alternator but damn...they are quite a bit to repair especially whent eh mechanic can't really pinpoint which one the problem is it could be a $100 or $400 problem...so my question is what is tension assembly and what could happen if i leave this problem alone...thank's fellas.

Hi fellas, i have a 2002 Mountaineer which check engine light was lit, it has two codes: PO401 and PO402. The local mechanic said that it needs the EGR sensor and they want to charge me quite abit on that...so i want to install it myself but i don't know where the it is located.....anybody know where the sensor is located and how to change it??? and anybody has any luck with their EGR problems.

Then i also experience some sqeuking noise coming from the engine. Upon inspection, the mechanic said that it could be the tension assembly or alternator but damn...they are quite a bit to repair especially whent eh mechanic can't really pinpoint which one the problem is it could be a $100 or $400 problem...so my question is what is tension assembly and what could happen if i leave this problem alone...thank's fellas.


It's not your egr valve. This has been a common problem with this era explorers and mountaineers. the problem is the dpfe sensor. it is a small thin sensor at the back of the engine (5.0) , closer to the pass. side right next to the egr valve. They can only be bought from the dealer and run about $100.00. The are a little tricky to replace though.