2001 Protege 2.0 random misfire - symptoms

DiS said:
do you actually get the misfire code or do you get a "CAT something something under threshhold"?

Two codes were read - Multiple Misfire and the CAT code. Mechanic says they're unrelated, but it seems to be awfully coincidental....
 
Last edited:
rtrussel said:
Two codes were read - Multiple Misfire and the CAT code. Mechanic says they're unrelated, but it seems to be awfully coincidental....

I assume its the 1st PRE-CAT CEL code. Its quite possible that the ViCS screw went through the cylinder head, came out through the exhaust manifold and on the way to the cat hit the o2 sensor. I presume thats what happened, but I might be wrong. 70/30 % chance.
 
DiS said:
I assume its the 1st PRE-CAT CEL code. Its quite possible that the ViCS screw went through the cylinder head, came out through the exhaust manifold and on the way to the cat hit the o2 sensor. I presume thats what happened, but I might be wrong. 70/30 % chance.

Thanks DiS,

I have been hearing a rattle from the CAT area and assumed it was just a loose shield - I'm now wondering if it's the ViCS screw bouncing around! Would this make sense? I'm up in Canada and there's a pile of snow everywhere, so getting underneath the car isn't too easy. On the plus side, it has 98+k kilometers on it and the warranty is for 100k, so I might just squeak this through if this is indeed the issue. I'm thinking of going straight to the dealer at this point as I don't want them to bulls*** me about it not being warranted if another guy starts pulling stuff apart. One thing I'm still a little unclear of though - why would fuel stabilizer temporary stop the hesitation? Is it just enough of a fuel boost to keep it going perhaps?
 
Misfire saga continues - more symptoms noted

Here's the latest - any advice is most appreciated!!

A few weeks back I left my car with the mechanic who could not duplicate the problem and basically told me that it would be guess work at this point and he didn't feel right replacing stuff that may not be the issue. Reasonably certain that it is not the VICS screw issue as I never heard any loud engine noises at any point, the symptoms don't all match and my model is an '01 LX, not MP3 (the rattling I heard was the cat shield as I originally suspected).


I did notice a few more symptoms lately, so here's an entire recap of my issue:

CEL flashes, diagnostics as follows:
Random Multiple Misfire
Cat under threshold something something....

Car will run fine, sometimes for days at a time, and then suddenly a hesitation will occur - no jerking, just a sudden loss of power. Stepping on accelorator does pretty much nothing. Car begins to slowly lose speed. Throwing it back a gear (I have a 5 spd) and punching the gas hard usually kicks the engine back to life. On at least one occasion, a substantial cloud (fuel vapor?) was emitted from the tailpipe when I did this.

A couple of times the car was parked downhill and the engine was extremely rough starting and to get going - it felt like I was nursing a stubborn carburator from the old days! A few times the engine has bordered on dying when coming to a stop and again nursing the gas gets it going. A few other times I was parked on a slight uphill grade and the car started to "chug" after idling fine for a few minutes. In general, grades seem to greatly increase the chance of misfire, whether parked or moving.

Car often feels slightly underpowered when driving. Also, when I let off on the gas, it seems to slow down a lot faster than I remember it doing before this problem.

Gas consumption has increased - I'm squeezing little more than 300 miles per tank vs. getting close to 400 before

Weather conditions appear to have no bearing on the problem.

Mechanic insists it isn't the EGR valve as codes don't indicate this and he doesn't think these symptoms match a coilpack issue. I questioned whether a clogged fuel filter could be an issue, but he said he never experienced such a thing on this model (esp. with the lower mileage) and again didn't want to touch stuff because of pure guess work. I appreciate his honesty, but on the other hand I can't keep driving an unreliable car.....


Things done so far:
Fuel pressure test was fine
New spark plugs
New air filter
Exhaust system inspected visually by mechanic
Computer troubleshooted
 
Last edited:
According to the workshop manual, a multiple cylinder misfire is possibly caused by problems on:

Ignition system
Fuel injectors
Fuel pressure
Evaporative emission system
Base engine
Crankshaft pulse wheel
CKP sensor (crankshaft position)
Low fuel or running out of fuel
CMP sensor (Camshaft Position)
Stuck open EGR valve
 
Sounds like the other misfire problem me and a couple other guys have had in another thread. So you have the random mifire and Warmup catalyst under theehold codes. Try switching your coil pacs to see if the misfires move to other cylinders. If so replace that coil pac. I bought mine at Rockauto for cheap but I hear they are back ordered. Also replace the precat O2 sensor. I bought a universal. Also clean your EGR valvle, even if the mechanic says that it isn't related, you have multiple problem and this will help at least part of your idle problem. Ultimately you could disconnect the pipe that goes to your second cat. If there is ash or residue buildup it is from the first cat which is the one throwing th code. Then you have two options. Get a new cat or get some headers that remove that cat.

Idle - EGR and Precat O2 sensor sends the wrong signal.
Misfire - Coils, if plugs have already been replaced.(check the gap too)
Cat under threshold - O2 sensor or/and cat

Hope that helps (cheers)
 
Let's see where this goes

Thanks Diehonda and solid_snake for your responses. On top of everything else, I just noticed that I've blown a rear wheel bearing - only a little over 60k miles on the car and it seems like it's pooched!! I'll get the bearing fixed and ask the mechanic how much to service or replace the egr valve - I've had a gut feeling about this all along.... Checking for a dead cat and/or O2 sensor replacement may be the next step. I'm unconvinced it's a coilpack at this point, based on the symptoms (ie. I don't think bad coilpacks give a "smooth" temporary loss of power, continuous loss of just some power or are affected by grades).

I'll let you know how this all turns out....
 
Yup its a really common problem..... will probably be the coil pack!
There is more and more of those random misfire problem... i assume its related to protege's getting older.....

There was like 2-3 thread about a same problem here in Quebec on another forum about it in 2 week and another one here on MSprotege.com.

Look at your coil pack because if one is defective, it might create misfire in that cylinder and affect the cylinder which the plug is connected to it
 
Me again....

Surprise, surprise, the cat blew out of the car, so now I've got some major repair bills with still no answer to the cause. I'm really stuck with this POS and I can't afford to guess and hope my way to things that may not even fix it. I suppose the logical thing would be change the cat and O2 sensor. If that doesn't fix original problem, change coilpacks. If no dice, EGR valve. If still no luck, god only knows.

My other alternative is to sell it for a cut price to someone else willing to gamble. I'm seriously considering doing this and getting an older Ford Escort that is more reliable.
 
what is the damage and your specific symptoms before the damage?
Just relax, there is always a way. Trust me I had a VW. (poke) I about rebuilt it before I sold it and it was a 2000.
 
Hi Diehonda,

The symptoms are the same as described in the Jan. 9 email in this thread - on top of this, I notice that if the loss of power starts and I put the clutch in until the engine nearly stalls, it runs ok again after giving it gas.

Mechanic checked the codes again and found the following:
P0300 - random misfire
P0302 - cylinder 2 misfire
P0421 - dead cat

According to these codes and the symptoms, he thinks the following is true:

Not an EGR valve issue
Not a coilpack issue (ie. random misfire has happened several times, vs. specific cylinder misfires)
Not a vacuum leak issue

May be a sensor issue
May be a computer problem or related electrical issue

He replaced a front pipe but not the cat to save me some cash, so I'm only a couple hundred bucks out at this point.

This uncertainty is killing me, but you're right, I need to relax a little....
 
Only reason I say relax is because like any car problem, it doesn't make a difference how much you stress about it, the problem still exists. I have been there and it blows.

Mechanic checked the codes again and found the following:
P0300 - random misfire
P0302 - cylinder 2 misfire
P0421 - dead cat

P0300 and P0302 are most likely related as one coil pack is shot as the other one is on its way out. I replaced both of mine(had the same codes) and went ahead and checked the gap and cleanliness of the plugs. This is the bogging that you are experiencing while driving. The reason why the coil packs are the problem is because these buggers are picky and will work fine for a day, part of a day, or a week and then not work worth a squat.

P0421 - dead cat could be the O2 sensor under your cat as they usually go out before the cat but throw the same codes.

Do a search either here or google on how to test the O2 sensor with a voltmeter. If the signal is weak replace the sensor. Get a universal, it is cheaper. Autozone had one for about $45.

If P0421 is the cat after testing the O2 sensor and it being OK, then you have to consider if just want to get an aftermarket header and a nonfouler. This is the route I went as the header range between $200 and $500. Where as a new cat at a great deal is $500.

Do you have emissions testing where you are located?

Never hurt to clean, not replace, the EGR valve. The how to here is straight forward and a snap to do.
 
Yo the kid DiS sounds like he's on the right track. You and i have the same car... and only about six months ago i had a similar problem. My loud clicking sound turned out to be a huge problem. Long Story short... i blew a Valve, a bearing fell into the piston chamber, and the end result was an engine in shambles. get it checked immediately!
 
Same Problems

I have a 2001 Mazda Protege ES 2.0 with same issues. Engine light was on for a few months with no problems noticed. Then CEL would occasionaly flash, but with no performance issue. Then when driving, I would loose RPM's and car would have no zoom-zoom to climb hills. I would have to keep it in 2nd just to get up the hill to my house. Idle would be all over the place, starting at 1500 RPM when first started for the day and under 100 RPM when it CEL began to flash. Took my protege in to have it checked. Computer showed random misfire and O2 sensor issue. I was told that the car was going into "Safe Mode" so the engine wouldn't be damaged. I Had spark plugs replaced but it did not resolve issue. The more I drove it, the more it had problems running smooth. Finally had coils replaced with used ones from local junk yard (shop couldn't find any new after market coils anywhere and new ones from mazda were over $100 apiece). Computer was reset and it seemed problem was fixed. Idle went back to around 700 RPM and car ran smooth. Haven't had "Safe Mode" happen again but CEL went back on.
 
green77 said:
Finally had coils replaced with used ones from local junk yard (shop couldn't find any new after market coils anywhere and new ones from mazda were over $100 apiece).


Next time go to Rockauto.com You will be surprised how much cheaper they are. It has also been stated that if you give the dealership the exact p/n that the coils are cheaper, they just look them up incorrectly on the expensive ones.

Welcome to the site, come back now ya here(headbang)
 
Hello All,

this is an old thread but I hope somebody out there is still keeping an eye on it. I have a Protege 2001 LS - with the 2 litre automatic. There are about 50 K on it. About six months ago I started having the symptoms described above, loss of power, drop in revs, mostly on the freeway but also sometimes turning at traffic lights almost stalled twice. I have brought into my mechanic multiple times, he started by replacing the EGR valve, but the problems persist. The Check engine light with come on, flash and then I'll get two or three Chugs in about two weeks. The last time I brought it to the dealership they had it for 5 days, put 600 miles on it but couldn't replicate the problem.

The error code is random misfire - I'm dealing with a new mechanic my dealership in Glendale sucks !

What would you suggest trying next - Changing the coils ?

Thanks a million as always for you're help.
 
Hello All,

this is an old thread but I hope somebody out there is still keeping an eye on it. I have a Protege 2001 LS - with the 2 litre automatic. There are about 50 K on it. About six months ago I started having the symptoms described above, loss of power, drop in revs, mostly on the freeway but also sometimes turning at traffic lights almost stalled twice. I have brought into my mechanic multiple times, he started by replacing the EGR valve, but the problems persist. The Check engine light with come on, flash and then I'll get two or three Chugs in about two weeks. The last time I brought it to the dealership they had it for 5 days, put 600 miles on it but couldn't replicate the problem.

The error code is random misfire - I'm dealing with a new mechanic my dealership in Glendale sucks !

What would you suggest trying next - Changing the coils ?

Thanks a million as always for you're help.


Replace both ignition coils. If it is a bit more pricey then you want then price a 1.8 ignition coil from a Miata or 99 Protege. There is a thread on her about the 2.0 to 1.8 conversion.


Welcome and good luck. The 2.0 ignition coils go on back order pretty often. Check the for sale section on this site for member part outs or hit up one of our vendors.
 
Thank you so much for the help,

I was starting to get really frustrated with my zoom zoom rocket, I love driving this car - although I should really have gotten the manual - and am such a huge mazda fan, having trouble has been a very traumatic for me, especially living in LA where breaking down on the freeway can literally be a matter of life and death -I'll get right on it and update with the any progress

Thanks again
 
Similar problems with my 2003 2.0 ES

Wow, reading this thread, seems like a fairly common problem. I've got 77k miles, and recently car started hesitating while driving, felt like misfiring. If I put it in neutral, car will drop in RPM's and almost die, fluttering the gas will eventually bring back the proper idle, and reving the car will usually fix the problem, temporarily. However, lately this is happening more often, like every 10 minutes of driving. and today, my CE light came on. Went to autozone and the code came back as P0401, EGR System Insufficient Flow Detected. I think this may be a symptom, not the root cause though.

I see alot of talk about replacing the "coil packs". On rockauto they sell an "ignition coil". Are these the same thing? (dunno)
 

New Threads and Articles

Back