Hi guys i'm seeking help troubleshooting my protege 99 1.6 L A/T.

How can i be sure that my catalytic converter is bad
Symptoms:
Slow running specially on hills
rough running.

104K miles

i have replace the spark plugs and wires recently

I have looked under the car and i'm not sure wich one is the catalytic converter becuase there is one in the bottom and the other almost under the cooling fan. can somebody help me?
TXS

 

READ THIS: https://www.mazdaforum.com/forum/maz...re-cats-28479/ from another thread on this forum.
It is not for your car but is a good help and understanding. The only real way to check catalytics is visually and/or backpressure.

I am not familiar with your vehicle. I just pointed out some generalities with good links to read.

 

i still have many questions but would be great if you can answer me this question.

The catalytic converter is the one located close to the cooling fan?

Then what is the name of the one underneath the car?


Thanks for your time.

 

There are 2 catalytic converters. As far as I know, the one by the exhaust manifold is called a pre-catalytic converter and the one you find under the car just behind the engine is called the catalytic converter.

 

I forgot to ask: Is the check engine light on? What are the codes?

 

Yes the check engine light is on!!!!
Codes
P0171
P0421
P0300

 

P0171= Lean condition, Bank 1 (the only bank you have)
P0421= Catalytic converter efficiency is low
P0300= Miss fire

It all adds up, Rusan: your engine is due for some tune up. I suggest you deal with the miss fire and the lean condition, then see what happens to P0421.

The lean condition is likely caused by a vacuum leak. That is a Mazda disease! Check the air intake hose for cracks. If you find cracks cover them with duct tape. Replace all vacuum lines with new hose from the reel. That's about $10.00 and eliminates a lot of potential vacuum leaks for years to come.
Replace the spark plugs, ignition wires, cap and rotor, and if necessary the coil(s).
Clean the MAF sensor with a can of MAF sensor cleaner, clean the throttle body with throttle body cleaner and open all EGR ports. ( I like CRC products).
Replace the air filter if needed.
Erase the codes by disconnecting the battery negative cable and stepping on the brakes.

Report back on what you found and how the engine reacted to your measures.

 

Pics of CRC products Tanprotege is talking about. +1 on Vac line replacement and everything else!

 

Thanks for all your tips TAN & USE YOUR NOGGIN really appreciate your time.

Just a couple of Questions:
Do you know the diameter of the vacuum hoses, i guess there should be different sizes uh!!!
I did not know that this car has a (cap and rotor) will look for them somewhere
Same thing with the EGR ports, i thought there was only one will look for these two!!!
Will comeback with results in a few.

once again Thanks.

 

Rusan: I t may not have a cap and rotor, my '98 does, but I am not sure about the '99.

You may pull a piece of vacuum hose off when you are at the parts store. I think I bought about 10' maybe 15' for my '98.

If you take the throttle body off for cleaning you need to replace the gasket, about $5.

Tan