Toubled PR5. Help?

[Hazardous PR5]

My '03 2.0 5spd Pr5 was coming up on 100K miles when the check engine light first came on. I'm meticulous about maintaining it and do it myself (oil changes at 3000mi, plugs gaped at 0.7, correct fluids, alignments, and octane boost/injector cleaner once a month). And she has always ran perfectly, however since the CEL came on I have thrown at least 7 codes and no one can tell me any definite way to fix the codes or the CEL. Off the top of my head, some of the codes were: random multiple misfire, valves stuck open, O2 sensor problems, catalytic codes, and those are just the ones I remember. While trying to narrow down problems and solution (mean while still driving it) I had my first real problem: While driving and cruising at a consistent speed, I lost power. Not total power loss, but it felt like a was down a cylinder... or 3. It wasn't misfiring or spitting but there was a huge power loss. I pushed in the clutch and the the RPMs fell to the bottom of the tac (200-50 RPMs or so) but the car didn't stall. The engine never shuddered or made any odd noises but after about 5-10 seconds of being in neutral the RPMs returned to a normal idle (about 1700 RPMs) and I put it back in gear and continued down the freeway, never having even stopped. This happened several more times seaming to occur about every 50 miles and only when I was at a low RPM cruise. I checked the O2 sensor, clean as a whistle, then cleaned the ERG valve which I found to be a bit sticky (at least I think it was the ERG valve. It is on top center of the valve cover, a black elbow, looks like PVC?). After that, the power losses seamed to stop or grow less frequent. However my CEL was still on. I was told to disconnect my battery and pull the fuse for the ECU for 5 mins to reset the computer and that if the CEL came back on, the first code it threw would be my problem. So i reset the ECU as I was told and after 97 mi it threw a cat code. My mechanic said the cat probably wasn't heating up fast enough and probably needed to be replaced.

Any one have any insight into my problem?

 

[kcbhiw]

It'd be helpful if you had the actual codes pulled (DTCs).

The valve on top of the valve cover is the PCV valve. The EGR valve is on the bottom of the intake manifold just passed the throttle body.

From what you describe, it sounds like you may have a bad EGR valve as well as a coil pack failure which, if left unattended long enough, will damage a catalytic converter (invariably leading to an O2 sensor reading fault).

 

[Hazardous PR5]

yeah, my CEL has been on for some time. I will search for the actual ERG valve. clean it, and possibly replace the coil pack. then reset the computer again and see what happens

 

[hornsfan10609]

I agree with kcbhiw, I believe the problem to be related to the Exhaust Gas Recirculation valve or the coil packs. Clean the EGR and get new coil packs/wires/plugs. Stock plug gap is .044" btw. And to reset the computer unplug the neg. battery terminal and pump the brakes a couple times then let it sit for 30 mins.
http://www.mazdas247.com/forum/showthread.php?t=94788

 

[Hazardous PR5]

ok thanks for helping a noob . BTW the gap is .7 mil or .044 inch. milimeters are easier to measure

 

[Hazardous PR5]

something else i've heard is the danger of running high octane too much. that the engine doesnt burn it all and leaves carbon build up. any truth to that?

 

[Ride92]

Sounds like a bad coil pack, I'd replace those first and see how she runs. Then look into the EGR valve.

 

[P-Funk!]

something else i've heard is the danger of running high octane too much. that the engine doesnt burn it all and leaves carbon build up. any truth to that?

No 'danger'. Just wasted money. Lowest octane is 'best' for us.

A good seafoam cleaning every 30K miles or so because we run so rich at WOT is a good idea.

 

[Hazardous PR5]

So I got some seafoam, put a little in the tank, a little the oil, and then went to run some throught the intake, and surprise, found my problem. my intake hose had a cut 98% of the way around it, right in front of the manifold. So I find this a great excuse to buy a cold air intake. Injen claims 6.1 hp, K&N typhoon clams 5 hp. Any thoughts?

 

[hornsfan10609]

I had the same thing happen to me last week. I couldn't find a name brand intake for less than 200, aside from the weapon R. I went with this kit because it was the cheapest one I could find with red couplers.
http://www.performancealley.com/product/MimoUSA-Short-Ram-Intake/Default.aspx?gfid=p533-c29490

 

[CheeseHelmet]

You could always go for the redneck fix and duct tape the pipe. I taped up a crack in my pipe and the car's been running much better ever since.

 

[hornsfan10609]

That's the way it is for now, but I wouldn't run it like that for very long.

 

[Hazardous PR5]

Yeah I realize duct tape will fix it, i just think its a great excuse for me to get a new intake like ive been wanting, just wanted to know who had the best intake for the PR5

 

[Justin2129]

I had the same thing happen to me last week. I couldn't find a name brand intake for less than 200, aside from the weapon R. I went with this kit because it was the cheapest one I could find with red couplers.
http://www.performancealley.com/product/MimoUSA-Short-Ram-Intake/Default.aspx?gfid=p533-c29490

were you happy with it? how hard is it to install? anything special you have to do or does it just fit on like a regular hose?

 

[dtre83]

i got the e bay intake and in the process of riggin it to work with the stock ram air on top of the radiator. p5 has good stock intake system from the tb out so not much difference in my opinion. just get the ebay intake and see what you think, 44 s&h

 

[hornsfan10609]

were you happy with it? how hard is it to install? anything special you have to do or does it just fit on like a regular hose?

Haven't installed it yet, I will let you know when it gets here.