Hi thanks for letting me join ..I have a 2002 Mazda tribute v6 keeps blowing off and melting the dpfe sensor egr pressure sensor when I put my foot down also I got no power at a 100km barely get over 120kmh ..I suspect I have a blocked cat but there's 3 of them I can rule out the one at the front of the car because that before the pipes to the dpfe sensor I was just wondering if I can rule out the rear cylinder cat which would make it likely the cat on the tail pipe mid car ..thanks hope my grammar doesn't put ppl off

 

Welcome to the forum glad you made good choice to join!!!
Hang tight we have a couple of veteran members that are well experienced with your Mazda Tribute. I am not one of them. Sorry .

If it helps Tributes are CAT eater. Often all 3 will fail or each showing indicators of failing. When our service customer's gets the estimate, they have on more than one occasion left the car with a unpaid diagnostic service charge and said keep it. In CA service shops are required by Law to replace the CAT with OEM or a replacement that is CA Emission compliant. so, about 1200+ USD. + labor In other states shops can get away with a universal CAT.
If you are not getting a rotten egg smell ,. check the operation temperature for abnormally higher. Naturally scanning the ECU for DTC specially looking at your I/M monitors will defiantly tell you if a CAT is the issue. Or if you have available anyone that has an EGA (exhaust gas analyzer) which would show very high HC's and Cos which will be generally the CAT. Or even a EGT (exhaust gas Temperature) which would show at idle registering over 700f + at the CAT if the ambient was 75f or cooler

To name a few ways to check out the CAT.

 

Thanks for that might just throw some parts at it if I can get them cheap enough starting with the last cat

 

If you suspect a blockage take out the first O2 sensor and take it for a drive. This will allow the exhaust gases to escape so you may have to make a heat shield to prevent the hot exhaust gases burnng anything but it will tell you if the exhaust is blocked.

 

Cheers for that don't know why I ddnt think of it

 

This is not a very good idea. It is dangerous to even recommend this on a forum for someone to try. Exhaust gases close to the head can be between 1000- as high as 2000f degrees.
Consider all the things close that can catch fire at or below 45f like fuel or 700f . Blue ribbon for the worst service suggestion of the year!

Now we will get the responses defending bad advise..

 

I have seen a cat so blocked the engine wouldn't even start.

 

Thats not so common as it once was. Most of the time now it’s do to oil consumption from bad oil control piston rings , an extreme cylinder wall glaze or bad valve guides.

 

I think mine is to do with blocked cats I can't see any other reason it would be blowing the dpfe worn rings would just mean less pressure I think

 

worn rings mean CAT contamination by uncontrolled oil entering the exhaust system.
A truly bad cat you would experience acceleration issue if it were partially or fully blocked, bad smell, and the opposite would be you exhaust would now be very loud. Cat act more or less like a muffler.
If you "think" its a CAT then why did you start a thread ask for help and yet have your own answer?