The_Judge

OK guys, here’s one for you (in usual essay stylee, sorry!)

I've had my standard UK MY00 for a month now. In the first week, I noticed an intermittent problem whilst accelerating hard. It felt like the car was "holding back". But I assumed it was just me, and that I was just imagining it, new car 'n all. It was still running on the tank of 95 RON unleaded the dealer had filled it with.

Since registering on scoobynet, and reading a few posts regarding fuel types, I've tried a tank of BP SUL, and a tank of Optimax. The holding back still occurred, but not as often. The Optimax seemed to perform better than the BP SUL, and was cheaper (which is nice!) I haven't tried Esso or Texaco.

Having now run several tanks of Optimax through the system, the holding back is still occurring, albeit infrequently. So yesterday, I decided to do an ECU diagnostic check, as per the instructions on saxonfields. No error codes. I then carried out an ECU reset. It took about 5 minutes of steady driving for the reset to complete. And when it did, the CEL indicated error 32 - oxygen sensor. But when I disconnected the jumpers and started the engine, there was no CEL. Took the car for a blast, and it felt quicker! I performed another diagnostic, which still indicated no error codes, and another reset. It took just over 10 minutes of steady driving for the reset to complete, only this time, no error codes!

Can anyone shed any light on this please? My guess is the sensor’s coming close to the end of it’s life. The car’s done 34K, and I know this sensor can go anywhere between 30K and 50K. Could it be anything else? As always, any advice/opinions will be greatly appreciated.

Regards…

scoobyslut

The ECU needs an "upgrade". a "hesitancy fault" has been noted with Subaru Uk, and are aware of the problem. get your dealer to contact them for an FOC replacement. end of story and also end of hesitancy!! had one fitted on my old one, felt like new car again after fitting, so does work.

The_Judge

Nice one scoobyslut! I'll speak to my dealer this afternoon. Do you think the oxygen sensor "fault" is a related issue, a separate issue, or a red herring...?

scoobyslut

Had previous occurrencxes with 02 sensor, but even after refit, the ECU was found to be the underlying cause of all faults.
I am not saying in your particular case, this is so, but shall we say, more "likely". The A/F [air/fuel ratio] sensor can also play up if out of parameter, should run between +3 and -3 anything other than, its faulty. So if it reads towards +5 or -6 then needs changing.
* it may take the dealer a few weeks to get a remapped ecu from subaru UK, but,like I say, well worth the wait, plus the fact, they pay, not you!! so even better...

The_Judge

Good work fella, very much obliged. Will make a phone call...

Incidentally, I'm now a regular!!! Drinks are on me.

Charlie_Boy

Be interested to find out if they do replace, i have the same problem but they told me it was a feature and i have to put up with it.

The_Judge

Will let you know how I get on...

The_Judge

One last thought. I'm in the process of modifiying exhaust system, possible air filter (although wary due to posts re. MAF failures!) and EcuTek re-map. Would a re-map fix my problems...?

scoobyslut

If changing air filter,suggest you lean away from any filter containing an "oil resudue", as it is drawn off by the passing air, some of which gets stuck on the MAF sensor, causing the MAF sensor to either fail totally or give wierd engine performance. You may have to watch as to where you go to get the ECU fixed if its "after" the exhaust swop, some of the dealers dont like seeing non gen exhaust/engine bits, as officially it voids the warranty, so maybe worth getting the ecu hesitancy cured first, then have a play.

scoobyslut

"Charlie boy", go back to your dealer, its not an "inherent feature", its the dealer you use, not knowing there is a "fix" for this fault, otherwise every turbo impreza would drive the same and Subaru would not be selling as many cars as they do and this site would be innundated with the same complaint.
So, go see the dealer, otherwise, get in touch with customer relations manager at Subaru Uk and he will apraise the dealer of the facts.

The_Judge

Yeah, read LOTS of posts from people with knackered MAFs. It seems K&N or Green seem to be the way to go. ITG seem to cause nothing but trouble! What I was getting at with the ECU was if I got a Tek2 remap at Scoobysport or Power Engineering, would that fix it? Because if I've got to wait a while for Subaru to sort it for me, I might as well not bother getting it fixed by them, particularly if I'm planning on getting it remapped anyway...?

chrome

fwiw, do you have a boost guage?
I had a failing MAF, and my boost was all over the place and gsve intermittent hesistancy as the boost skipped about..

try a new MAF sensor.. plenty of MAF threads about lately- mine included..

it solved my probs.

The_Judge

No, I haven't got a boost gauge unfortunately. Yeah, saw your posts a couple of days ago re MAF. Don't think that's my problem though. My warm idle speed is more or less perfect (assuming 800rpm +/- 50 is perfect!). I also tried removing the MAF whilst the engine was idling; whilst cold, the revs wavered, but recovered. Whilst warm, the car stalled. Am I correct in thinking the revs wouldn't have changed if the MAF was knackered...?

Jay m A

iTrader: (2)

BTW, I think the TEK2 would solve the hesitation, since I belive a TEK1 is basically just that - a MY99 map to replace the hesitation prone MY00 map.

The_Judge

If that's the case, I'll live with it until I can afford the re-map. I just took it for a blast, and even with today's temperature, it went well enough So if the MY99 ECU has a better map than the MY00, why the hell did Subaru mess with it Are there any advantages of having the 00 over the 99?