My 2002 Protege5 is no longer able to easily make it up even the slightest of hills. It doesn't miss, nor generate an error message, just slows forcing a downshift. I'm the original owner, and it has 75K miles. It's a 5-speed. The problem started after I tried platinum plugs. I switched back to regular ones, but the problem persists. I was going to change ignition coil and wires, but was told if they were the problem I'd have an error code, and that fuel filter (sock) probably is clogged, which the computer would not notice. But I've seen no other discussions of this problem. I appreciate all suggestions, especially knowledgeable ones 8^). Thanks!
Protege5 has no power going up hills. No error code. OK on level roads. Cause?
- Thread starter dwryter
- Start date
My P5 was fine, plenty of power going up hills, until after the spark plug change. That's why I suspect the problem might be an ignition coil; perhaps using the platinum plugs fried one? If so, would that necessarily spur an error code, or could it happen without startling the computer? Or, maybe the timing of the problem is coincidental, and loss of power is due to some other reason. Last week I drove a friend's 2002 P5, and was reminded just how much loss mine is suffering. Even with four of us aboard, his sailed up hills with no problem. Like mine once could do, but no longer.
How do I reset the computer? Do I have to disconnect the battery to do so?
How do I reset the computer? Do I have to disconnect the battery to do so?
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whatusername
Member
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- 02 protege5
yes disconnect the battery and make sur ur plug gap is set correctly.. dont trust the gap they come with..
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- Mazda, Protege5 2002
are you sure there are no other symptoms? pay a bit more attention, there must be something more that just not being able to go up the hill
Can you check the back pressure on the first catalytic converter? It is the one that is connected to the exhaust manifold. You don't have a lot of mileage, but poorly performing spark plugs would cause the engine to push more unburnt fuel into the exhaust gases that would then clog/ruin the cat.
Before posting here I had already checked and re-gapped the plugs (two were 2/1000ths off, correction didn't help), checked all connections, examined (and smelled for signs of burnout) the coils and wires, and dumped in a bottle of injector cleaner and premium fuel (not 87 like usual). Other than the lack of power going up hills there are no symptoms. (Very sensitive to such things, I'd have noticed.) P5 still can leap across an intersection, idles and runs smoothly, doesn't overheat, doesn't burn oil. The battery was replaced after the problem started, so the computer already has been power-cycled at least once. That seems to leave as possibilities the ignition coil/wires, plugs (though not likely, as I've tried two new sets, one of the platinum), fuel-filter sock, perhaps a compressions problem, or the cat converter. Rit4623, how does one check back pressure on the first cat converter? Also, if I need to change the coils, aftermarket ones cost 1/3 to 1/2 that of Mazda OEM. Would they be effective, or best to stick with original? Thanks, guys!
what plugs you got in there now that you took out the platinum ones? What part number and brand?
NGK BKR5E (BKR5E-11 are pre-gaped) is all you need in there, less then $2.50 a piece gapped to .044. That engine should run strong. Dont over complicate with expensive s***-tanium plugs specially autolites or auto-craps as i call them (i really don't like the products they make)
NGK BKR5E (BKR5E-11 are pre-gaped) is all you need in there, less then $2.50 a piece gapped to .044. That engine should run strong. Dont over complicate with expensive s***-tanium plugs specially autolites or auto-craps as i call them (i really don't like the products they make)
kosteniuks17
Member
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- Mazda Protege5 2003
I think its mostly due to carbon build up over time... Also the cars get like 95 hp to the wheels so its not like there much power in the first place plus after a few hundred thousand miles im sure our cars are getting like just over 70-80 hp. This car wasnt meant for power it was meant for a fun, stable, twisty car. I installed some v-power long reach and i thought it helped it out a good amount. I dont think the wires will change much, i put some NGK for like $20 and i think they are doing just fine.
You need to get a back pressure tester/vacuum gauge where there's a threaded connection on the other end of the gauge. You remove the upstream O2 sensor that is in the exhaust manifold. Screw in the back pressure tester into the upstream O2 sensor hole. Have someone start your car. Look at the gauge. It should be 1.0 to 1.25 psi or lower at idle. Have the driver rev the engine to 2,000 RPM. If the backpressure is 2.75 - 5 PSI, then you have too much backpressure which would indicate a clogged cat. Don't run the car too long without the O2 sensor.
