What have you done to your P5 today?

What did I do to it today? I sat in it after driving home from the store, wondering why I am getting a P0421, Low Cat Efficiency code even though the Cat is less than a year old, both O2 sensors are new, new plugs, wires, air cleaner, intake tube, and several other tune up parts, and no other codes at all. Car seems to run just fine and gets very good MPG. 03 with barely over 150k miles. I clear it and go several weeks, checking constantly with my Bluedriver OBD connection and a lot of times have the code pending, but other times not. It will actually set every several weeks or so and I clear it. Started about 6 months after Cat install. Any suggestions?
 

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Which brand O2 sensors? I've read some folks have bad luck with cheaper or off brand ones.
 
Found a really nice clean Yellow MSP at my local yard.

...

I grabbed the rear calipers, MSP floor mats and door sills, and an MSP engine cover which doesn't appear to fit even remotely onto my FS-DE, so going to have to figure that out.

The cover requires a valve cover from the MSP as its valve cover has areas for 4 studs to mount the cover on. You'll also notice the MSP's valve cover doesn't say mazda on it.
 
Any suggestions?

This will get rid of your code,..
(You should only need to use one.)


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The only problem with it, is that one particular brand of O2 sensor doesn't fit inside the spacer.

And I think that it's Denso that's too big?

We used to have to drill out a spark arrester and stack it on another one, but they are available in the longer length now as an O2 spacer.




I just found this,..
It's the Bosch that's too big.

 
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If you can, buy some paint protection film (like the 3M scotchgaurd stuff) to put onto those headlights and foglights after you sand them so they don't immediately fog over. Did that on my headlights and though the PPF wasn't the cheapest and was a little challenging to apply, I think it'll be worth it in the long run to keep the headlights clean and clear!
thank you, much appreciate it..
 
Wow, haven't been on this forum in a loooooooooong time and this thread is still going?? OK this is what I did to my JDM Mazda RX (1.5L w/variable phase cams), with about 196,000km on it). Several weeks ago my mechanic replaced the camshaft and crankshaft position sensors. The camshaft position sensor connector was broken so he had to zip tie it to keep it inserted. I bought the connector pigtail off of alibaba, cut off the old connector, soldered the wires of the new pigtail and connector, heat shrunk it, and wrapped it up. And it still runs. Yay!

The 2002 Midnight Blue MP5 that I brought over to Japan like 12 years ago is driven very sparingly (idiot drivers here here in Japan have wrecked it 2x) needed a wash, so I washed 1/2 the car. Will do the other half next week. LOL Need to find a power folding mirror solution for it...
 
Wow, haven't been on this forum in a loooooooooong time and this thread is still going?? OK this is what I did to my JDM Mazda RX (1.5L w/variable phase cams), with about 196,000km on it). Several weeks ago my mechanic replaced the camshaft and crankshaft position sensors. The camshaft position sensor connector was broken so he had to zip tie it to keep it inserted. I bought the connector pigtail off of alibaba, cut off the old connector, soldered the wires of the new pigtail and connector, heat shrunk it, and wrapped it up. And it still runs. Yay!

The 2002 Midnight Blue MP5 that I brought over to Japan like 12 years ago is driven very sparingly (idiot drivers here here in Japan have wrecked it 2x) needed a wash, so I washed 1/2 the car. Will do the other half next week. LOL Need to find a power folding mirror solution for it...
You drive a USDM Protege5 in Japan? That's sick! Couple of people on here with P5s in other countries but not Japan that I've seen.
 
Just completed a MSP rear brake swap - calipers, rotors and pads. Pretty straight forward once I had all the parts.

Feels really good. Nice to have a parking brake again too. Really hoping this setup lasts longer than the P5 brakes I had on before which kept seizing and causing problems. I think my rear rotors are larger than my fronts now too, by a good bit.
 
Just completed a MSP rear brake swap - calipers, rotors and pads. Pretty straight forward once I had all the parts.
I have to say I am not a fan of the MSP rear calipers. Had to buy a special tool to adjust the piston and you can't even do the adjustment with the caliper on the disc. How does that make sense?!
 
I have to say I am not a fan of the MSP rear calipers. Had to buy a special tool to adjust the piston and you can't even do the adjustment with the caliper on the disc. How does that make sense?!
I did notice that. I used a pliers to rotate the pistons back and it was super easy. I guess I've heard the MSP calipers have less issues with seizing which is why I went with them.

I've gone through multiple new and used P5 rear calipers on both sides in the last couple years and was absolutely done with it. Only thing so far that has actually made me consider getting a new car because I was so frustrated with how crap the quality has been. Hoping the MSP stuff is good and I don't have to touch it.
 
Just did the fix for the ac on speed 2 and 3. Works absolutely great. Used a guild on youtube and the hardest part was getting the aftermarket bezel out of the dash. 10/10 would definitely recommend for anyone with the issue. Wired a resistor and a diode I believe into the sense wire and into the ground. 30 min job.

Next on my list is a fresh solenoid block and solenoids plus filter with Lucus trans fix to see if i can tighten up the shifts a little and get better gas mileage. Hopefully get some power back in the pedal.
 
For anyone in rainy areas, this job is a MUST. Making sure your vapor barriers are intact so they keep moisture out. What happens is the black sticky goo that holds the plastic onto the door will eventually stop being sticky and the plastic doesn't stick to it or it sticks to the plastic, but not the door. This is how your carpets get wet and this is why your windows fog up over night after it rains.

Also, as a bonus, I installed several pieces of audio mat to the doors and they shut with such a satisfying European “thunk” now. Should have done this years ago. Now I only have to do it on both of the MazdaSpeed Proteges.

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For anyone in rainy areas, this job is a MUST. Making sure your vapor barriers are intact so they keep moisture out. What happens is the black sticky goo that holds the plastic onto the door will eventually stop being sticky and the plastic doesn't stick to it or it sticks to the plastic, but not the door. This is how your carpets get wet and this is why your windows fog up over night after it rains.

Also, as a bonus, I installed several pieces of audio mat to the doors and they shut with such a satisfying European “thunk” now. Should have done this years ago. Now I only have to do it on both of the MazdaSpeed Proteges.

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I always hated how flimsy the Protege doors felt when closing, even compared to other crappy cars like 90s Fords and Hondas!

I definitely need to do both of these on my P5.
 
Next on my list is a fresh solenoid block and solenoids plus filter with Lucus trans fix to see if i can tighten up the shifts a little and get better gas mileage. Hopefully get some power back in the pedal.
Lentech still makes their Street Terminator AOD valve body with all the solenoids delivered for around $600 and it is SWEET! You'll have to talk to them directly but they built one for me a few months ago even though it's not on their price list any more. Definitely more aggressive shifts at higher rpms!
 
For anyone in rainy areas, this job is a MUST. Making sure your vapor barriers are intact so they keep moisture out. What happens is the black sticky goo that holds the plastic onto the door will eventually stop being sticky and the plastic doesn't stick to it or it sticks to the plastic, but not the door. This is how your carpets get wet and this is why your windows fog up over night after it rains.

Also, as a bonus, I installed several pieces of audio mat to the doors and they shut with such a satisfying European “thunk” now. Should have done this years ago. Now I only have to do it on both of the MazdaSpeed Proteges.

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For anyone else who needs to do this, I replaced the vapor barriers in my msp completely, the material that holds on the plastic sheet is butyl, and with enough time and effort you can get it off pretty cleanly with a solution like Mineral Spirit. The plastic was completely shot on my car so I got some of those paining plastic sheets from Home Depot to replace the old. Also definitely put some sound deadening in there, kilmat is a good bang forbuck, I think i went a bit overboard on mine. So, once the butyl is cleaned off, you can place the rope in its place, after that I cut a square of the new sheet out- roughly the size of the door and placed it over. Make sure you push some plastic in where the old black cavities were on the old sheet, I ended up making mine a bit too tight- however it still worked fine. You can cut the sheet along the butyl afterwards with sharp scissors. The only gripe I have about the job I did was that I forgot to take a pic of where the door handle hole was in the plastic and ended up needing to cut all along the wire to get it to work- as i made a hole way too close to the end. And I would also try to make the plastic sheet a bit looser if I could do it again as you can hear the plastic rubbing when opening one of the rear doors since I put the plastic in too tight.
 

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This car has been pretty good to me in the last 6 months, which is probably why I haven't been on here too much.

I just checked on my stock front brakes because I'm starting to hear some noise, and the outside pads have plenty of life but the inside pads are basically shot. They're Hawk HPS pads which have been great and I'm happy with 45k miles out of them considering how I drive. But the difference in rotor size from the stock fronts to the the MSP rears is hilarious, and since I need new front pads, I might see about a Mazda 6 brake upgrade depending on how much more I can squeeze out of the front pads.

Found a cool photo spot...you can kind of see the difference in rotor size front to back 😛

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The other thing I did was a transmission and brake fluid flush along with a braided clutch line. The transmission fluid had 35k miles on it and the 2nd gear synchro was starting to feel really bad, but 1qt of synchromesh + Valvoline gear oil for the rest made a huge difference to smoothness, especially at lower temps. The braided clutch line was an attempt to further smooth out shifts, but ended in a replacement master cylinder reservoir and a full brake fluid flush with high quality Bosch fluid which I was hoping to do already.

Also replaced all of the VICS/VTCS/Fuel pressure regulator solenoids that just kept throwing CELs. No more intermittent CELs.

Lastly, did a checkup today on the timing belt. 206k miles and no record of it being changed (and it looks OEM), so I was a little nervous about it leaving me stranded in the middle of nowhere. Took the valve cover off and it looks great still. No cracking and no missing teeth. Don't have any reason to believe it'll just snap, so I'm going to full send and wait until it breaks or is convenient for me to replace. I can't imagine at this point that it wasn't replaced at some point, otherwise it would have snapped already. This car has regularly seen redline under my ownership and lives in a very cold climate. Top end seems clean and in good condition too. Other than the fact that it smokes after sitting for a couple of days which is probably valve stem seals.

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Next up is some wrinkle paint for the valve cover. Just need the time for that and to replace the PCV stuff which is leaking. Oh, and bought sound deadening and butyl tape to seal the doors.

This thing just goes and goes and I love it.
 
I'll anecdotally chime in and say I got to 209k I think, on my Pro5 before the teeth on the timing belt let go. I lost 9 teeth while sat idle in the college parking lot. And thankfully that's where I was. The belt held intact which was convenient.

I checked the belt prior to this as I was also lead to believe it hadn't been replaced. Non-interference engine was lovely since nothing got damaged, and I was only inconvenienced.
 

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