99 Ranger Check Engine Light code P0402

'99 Ranger flex fuel 3 liter engine. I was getting a check engine light on the instrument panel. Went to AutoZone and got my codes scanned, P0402 (Exhaust Gas Recirculation Flow Excessive Detected) showed up. Removed the EGR module and checked the diaphragm, no problem. Before removing the EGR valve I had disconnected the negative side of the battery. Anyway, after reinstalling the EGR valve I reconnected the negative cable to the battery and started the engine. The check engine light went off. Ok, I thought the situation was fixed.

However, about 6 weeks later the check engine light comes on again. This time I didn't mess with the EGR valve, I just disconnected the negative cable and then reconnected it. Again, no check engine light. Question, any guesses as to what is going on? Is it likely that the check engine light will come on again? Anyone else with this problem? How did you fix it? I'm not a mechanic by trade. Any suggestions? Thanks, Lee

Reply to
Lee
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Your clearing a code that set without fixing the problem. Now a vehicle will not set a code until certain conditions have been met, and in some cases met several times. If your car sets a light, while pulling a load up a hill and your took it to a shop and they replaced something and reset the light. 6 months down the road, no light, they must have fixed it! 3 weeks later you pull the hill again with the same load at the same temperatures and...another light. In some cases it took 7 months for the drive cycle (The testing of that area) for that system to finally complete itself and see that there still is a problem. Now the code is telling you that too much egr flow My research into this code for Fords show the DPFE sensor (I believe they are talking the EGR sensor) replacement. This is a common repair at our shop, is to replace the EGR valve and controller.

There is also the chance that it is another different code.

Reply to
Steve

Thanks Steve, I will look into this.

Reply to
Lee

Did you replace the EGR Module, or just clean the diaphragm? Maybe it is telling you that you should replace the module.

( I ad the same light on my 4.0 l V6 a year or so ago, and after I replaced the module I noticed an improvement in fuel mileage. You are probably not wasting your money by replacing the module...)

\H.

Reply to
Simon1952

Nope, didn't replace the EGR valve, just checked the diaphragm with a vacuum pull-down -- seemed to work ok. Anyhoo, I'm going to check the DPFE sensor next before buying anything. In the end I may have to replace both EGR and DPFE sensor per the previous poster (Steve) but I want to do the simple things first. Thank you for your suggestion.

Reply to
Lee

does anyone know roughly how much these parts are to replace?

Reply to
Chris

The DPFE was about $70 last time I bought one from Ford.

Reply to
gw

If memory serves me, check the local Mazda dealer. Here in the GTA they have been known to sell ford parts at a cheaper price.

Reply to
905guy

Thanks for the heads up! Any comments on their service? I don't plan on returning to my local Ford service facility unless absolutely necessary.

Reply to
Roy Brown

Went through the same with 98 Ranger with same engine. Replaced the valve, module, and a third component whose name escapes me. After replacing valve, problem returned. And instead of making repeated trips to dealer for parts, just replaced other two components, problem not returned in about a year. IIRC, $185 for all three parts.

John H.

Reply to
mustmaker

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