[waughoo]

Okay... I finally decided to just replace the barometric pressure sensor and the EGR boost sensor solenoid. These are the two "gizmos" on the firewall above the EGR valve at the intake (see pictures). The part numbers I could find off the parts I removed are as follows...


Baro sensor: KL47, E1T10372, A 4526
EGR Boost sensor solenoid: K5T49096, BP4Y, 4427


Both of these parts are made by Mitsubishi. Using one of the two links provided by @DrFeelGood above, I was able to buy the EGR boost sensor solenoid. The one the Doc listed for the baro sensor is actually a MAP sensor that goes in the air intake and is not the correct part for this application. It is likely the same gizmo inside the plastic, but the wrong orifice for the baro sensor needed for the EGR system. I found my Baro sensor on EBAY listed as an OEM part. I had thought I was getting another Mitsubishi part as that's what they had pictured, but it turned out to be manufactured by FAE. I was a little disappointed with that fact, but I will live with it as it is still a new part rather than used.


Wide angle shot of the parts on the fire wall for situational awareness

Close up shot with the Baro on the left and the Boost sensor solenoid on the right

After replacing these two parts and then driving to the parts store to have them clear the codes (I still don't have a code reader), I have now driven 100 miles and the check engine light has stayed off. The interesting thing is that the boost sensor solenoid checked out fine out of the car. It held vacuum as explained earlier in this thread and changed correctly when 12v was applied to the contacts. I didn't test the Baro sensor, as I was just a bit tired of the problem. So I'll never really know what was wrong, but it appears that the issue was with these two sensors on the firewall.


As I stated in an earlier post here, I did see some improvement (check engine light stayed off for a while) with cleaning the EGR probe tube, that did not keep the light off. I feel like it did need to be cleaned though, so I'd likely suggest that as part of this repair that the EGR tube should be cleaned and then those two sensors replaced on the fire wall. I'll be going in tomorrow to get my emissions test as I need to renew my tabs. I'll report back if it stayed off long enough to get to the testing station and if I indeed passed. I'm feeling pretty confident now that I've logged 100 miles though.

 

[waughoo]

So in my obsession with a solution to this issue, I came across this post in another forum. It appears to be a non vehicle specific repair forum meant to help troubleshoot error codes and scan data from the OBD scanner. They are for the exact same two codes as this thread. The interesting thing I spotted was that the guy bench tested the solenoid and it did everything it was supposed to do, but it was still throwing the code. Eventually, he replaced the solenoid with a new one and the code cleared. It makes me curious if there's a resistance value in the solenoid that the computer wants to see. Regardless, I plan to change both the solenoid and the baro sensor (parts ordered) and will replace them when the new ones arrive. I'll report back.


https://www.scannerdanner.com/forum...ner.com/forum/post-your-repair-questions-here/3560-mazda-6-p1487-and-p2227.html

 

[waughoo]

Thanks Doc. I bench tested the solenoid valve and it worked correctly out of the car. I was a bit too lazy to perform the factory test for the baro sensor, so I just decided to buy one. The one you have listed above is almost correct, but I was able to find the right one after a bit of searching with the part number on the one in the car. I'll report back after I've tried it out.

 

[waughoo]

@DrFeelGood thanks for the info. Any chance you found part numbers for the boost sensor solenoid and the baro sensor?

 

[waughoo]

@b1lk1 I'll check into it. I haven't touched the air box at all so I suspect that if this is the issue, the sensor had failed. Do you know how to test the sensor/motor?

 

[waughoo]

P1487 has NOTHING to do with the EGR valve. You are using generic codes definitions. For us, this code is for the variable intake air valve (not sure if this is exactly right) that is attached to teh side of the factory airbox. If you have a CAI, you need to remove this valve (has a green plug) from the airbox, plug in the sensor and just put it off to the side somewhere.

@b1lk1 I am running full stock set up for the intake/air box. What is Mazda's code say for that?

 

[waughoo]

So, I've been using this thread to troubleshoot my P1487 code. I've removed the EGR and found it to be plugged at the tip. I cleaned it and put about 25 miles on it and the code came back. Without interference from me, the DTC will go away (idiot light on the dash), when I drive solid freeway at full speed for about 20 miles. However, once I start driving on the street again, it will reset again illuminating the light after about 5 or so miles. I'm thinking that it's likely the boost sensor solenoid at this point, but might still be the baro sensor. I've looked on Jim Ellis Mazda parts and can't find these two parts (the ones on the firewall). Does anyone have part numbers for these two parts (baro sensor and boost sensor solenoid)? Neither of them shows up on the Rock Auto page either. Thanks for your help.

Hey @waughoo, are they circled in the picture below?

Yes... those are the ones @DrFeelGood

 

[waughoo]

So, I've been using this thread to troubleshoot my P1487 code. I've removed the EGR and found it to be plugged at the tip. I cleaned it and put about 25 miles on it and the code came back. Without interference from me, the DTC will go away (idiot light on the dash), when I drive solid freeway at full speed for about 20 miles. However, once I start driving on the street again, it will reset again illuminating the light after about 5 or so miles. I'm thinking that it's likely the boost sensor solenoid at this point, but might still be the baro sensor. I've looked on Jim Ellis Mazda parts and can't find these two parts (the ones on the firewall). Does anyone have part numbers for these two parts (baro sensor and boost sensor solenoid)? Neither of them shows up on the Rock Auto page either. Thanks for your help.