Hey guys - I haven't been on here in ages, but I know its the right place to ask...

So a month back my Mini started randomly losing power and sputtering to the point of feeling like it was going to stall out on me. I could press the clutch, and was able to rev the engine just fine with no hesitation, but upon putting it back in gear, it was back to feeling really bogged down. I can only describe it as a feeling like it wasn't getting fuel or something. I parked it and the next day, I had no problems.

A couple weeks ago, the issue popped back up again, and I realized it seemed to happen while going up minimal inclines both times. (not sure if that had anything to do with it). I decided it wasn't just a fluke, and began to look at areas where an issue like that could be caused - Air and Fuel. I filled my tank with V-Power (as it was close to empty), gave the car an oil and filter change, and replaced the air filter (which was in desperate need). The car right away seemed like a whole new beast and I thought I had cured the problem.

The next day, the car didn't feel like that new beast anymore. Not sluggish or anything, but back to it's normal operating mode. But I had no "almost dying" issue, so that was nice. Went a few days without issue actually. Then it happened...

The other day I slowed at a yield sign, then was ready to merge and the car was suddenly back to almost completely dying on me, so I pulled over and let it idle. After a couple minutes, I revved it up, and pulled into the travel lane. The whole way home - unless I was above 3000rpm, the car seemed to struggle. It was then that I realized that all three times it had happened, was when there was water all over the pavement. No deep puddles, but water from snow melting and salt being put down on the roadways to melt ice and such. So now I'm wondering if the water spray is possibly causing it.

I'm at a loss, and would love anybody's advice on what to look into next. I plan to change out the fuel filter soon as well (even though, I'm not sure that is the cause, as it's so sporadic). I checked out my wires, and they are all nice and solid, and the boots are well seated. Haven't checked the distributor, but if it was getting water in it, wouldn't it be a constant problem until it were dry? I doubt revving the engine would work just fine if that were the case. So I'm wondering about air control (Mass Airflow Sensor, O2 Sensors, etc) perhaps... I don't know.

Please help...

 

how many miles? any idea how many miles on the plugs/wires? any mods? any codes?
r53 does not use a distributor...but a coil...you can check it for corrosion on the plugs...very common on the oem coil. the wires are very short, and rarely fail, BUT you say it happens when moist....if miles are high, might be worth the $35 to rule them out...
also no mass airflowsensor...uses a t-map and a map.....

 

Ok... 100900 miles on it right now. Replaced the plugs and wires about 8000 miles ago. No mods. And I'm not sure about any codes - nor am I sure how to check for any without bringing it in to a shop (I don't have a diagnostics computer)

 

have heard of a person having issues with the pickup hose in the fuel tank failing...cracking..gave them issues below about a half tank...
so.. i might try keeping the tank +75% full for a few days...see if it does it again...
if the coil is original...might be getting iffy...about a $75-100 part....
if you have a yellow "check engine" or "eml" light, you have a set code....can't check for a "pending" code, no light yet, unless you have a $40-200 tool to read the errors..but even a set code needs a reader...some auto places will read them for free....

 

Right before I replaced the air filter, the Service Engine Soon light came on. It was back out right after I changed the filter and started the car up though. Would that still be saved?

If the coil is the culprit, would it only appear when the roads are wet though? That would seem like a more "all the time" type of problem to me.

I will also keep the tank topped off for a solid week and see how that goes. Is the pickup hose as easily accessible as the filter and pump?

 

Sounds like you are in limp mode. If so, there is a code. I'd have a dealer or independent check for codes. Without a code, it's anybodies guess..

 

How can you tell if it's in limp mode. And would just any old random thing send it into that? (dirty air filter, oil level, bad coil, etc)

 

Ok guys... Code that is coming up is:

P0130
O2 Sensor Bank 1 Sensor 1

Picked up a Bosch universal sensor, but haven't installed it because I've read a lot about how they still throw a code and the SES light. What do you guys think? Is the sensor finding a different problem, or is it the problem. And do I really need to spend ~$200 on an O2 sensor just to clear the code?! Is there any aftermarket's that match up for less $$, or what?

Also, does this item match up to OEM specs?

http://pages.ebay.com/motors/link/?nav=item.view&id=251803005616&alt=web

 

I would NOT use an "universal" o2...
The end will need to be soldered to the factory plug on the old one...and the other sensors are in wet, vibrating locations, and changing the wire length can change the impedance, thus the reading the computer THINKS it is getting...
Now I doubt the o2 sensor is causing your issue, it likely is bad...
One tip...the OEM sensor can be had for much less than the dealer pricing...lots of posts on WHICH sensor is the oem around...maybe somebody has the info and will chime in, or do a serch...use advanced...it is much better, or google "site serch".
And even then the o2 sensor MIGHT be a free fix...some 2005/2004 cars got an extended warrenty on the o2:sensors....so worth calling the dealer with your Vin to see if you qualify...

 

https://www.northamericanmotoring.co...-obd-code.html
Check this thread...might help with the code...first one I looked at...

 

Thanks for all your input. Its really appreciated.

Just FYI, the universal has an OE SmartLink Kit, that makes it solderless to ensure oxidation doesn't occur, and its waterproof. Doesn't fix the code flagging, but just figured I'd let you know about how it connects to the old system.

I plan to get the car up in the air tommorow and check the pre-cat exhaust area for any compression issues. I was listening closely to it, and I think there may be a small hole or something. If water were able to get in there, and if the compression is off, I can only assume that would possibly get the O2 sensor to misread things. What do you think?

The fact I have just over 100,000 miles on the car, takes it out of warranty for the O2 sensor as well. Which blows. I swear it waited until I just barely rolled over to the six digit mark, to fail. Bastards! I'll end up changing it out regardless. It's due anyways, at this point.

 

Front and rear o2 sensor is the same...
So I suggest the "good" one...the one you trust is in the front to adjust the mixture...and the rear, that monitors the cat is the one you are not sure of....
100,000 miles on an o2 sensor is not bad...got 230k on one of the 3 on the wife's Toyota has highlander......the other 2 went around 170,000....but no complaints....just sold it...
Know you are a bit far out...but Pete at Greasysgarage in Worcester Ma is a good fallback if you need more help....I happily drive an hour to see them when I need too...they know gen1 cars VERY well...you might still need to have the o2 sensor code reset by him....the o2 sensor can be a "hard" code that is not possible to clear by a normal odb2 reader, except by a large amount of time...something like 40+ cycles if I recall if you have the time before inspection....

 

And a small exaust leak ahead of the o2 sensor WILL cause an o2 sensor code...o2 will sneak in...and cause issues...heck...a leaky manifold or cracked header pipe, or even a failing cat if it melted MIGHT be your issue...not sure...but something to consider...
100% fix the leak BEFORE you start swaping sensors....