Check engine light, ticking noise

We purchased a 1999 FOrd Taurus in April. It has 44000 miles on it as of today. A couple of months ago the check engine light went on, took it to Autozone, they hooked the computer up to it and the EGR valve came up. We replaced it (the next day), light came back on, went back to AUtozone, the kid cleared the computer (I"m not suppose to tell anyone he did it). THe light came on the next day. Thought it was a defective EGR valve, bought a new one, replaced it, light came back on. Again, thinking it was a defective one, replaced it, took cable off battery for 3 days, light came back on. Autozone keeps saying it's the EGR valve popping up on their computer, but when we replace it, the light comes on the next day. Also just recently we have a ticking noise coming from the drivers side of the engine, towards the front window area. There are no belts there, it seems its from the oil dip stick area, can't really pin point it. WIth the hood open there is a very distinct ticking noise. The ticking doesn't happen all the time, but I want to fix it before something major happens. Thanks!

There are two other sensors that may be causing yuour problem. One is the EVR (EGR Vacuum Regulator) and the other is the DPFE (Differential Pressure Feedback). May be more, but these are two that I would be checking into. As far as the ticking noise, hmmm. Might want to check for a bad plug wire where the spark is jumping and causing the tick. Could be a lot of things but without being there it is difficult to diagnose.

Thanks so much for the quick response! Do you think these sensors have anything to do with that 'ticking' noise on the lower part of the engine? Or is that a different coneren. Thanks again!

I wouldn't rule it out but it would not be my first choice.

Again, Thanks. I'll have my husband check into these things you suggested. I truly appreciate your knowledge and time!!

You might have a bad O-2 sensor. My 1999 Taurus has the same problem. A buddy from a Ford dealership told me to replace the O-2 sensor in Bank #1. I am trying that tomorrow morning to see if that fixes it. I'll let you know.

Thank You so much! Please do let me know, this is really driving us crazy!