Phat DP & Phat Quad tips fitted, now CEL errors :-(

[dwayne]

Hi All,

**UPDATE**
guys, to put this to bed, it was a hose not reattached to the BOV. Kudos to Phat for nailing it straight on.

I'd like to say at no point was I questioning the quality of Phat's gear - it is fantastic.
**END UPDATE**

got the Phat Quad tips and Phat DP fitted to my 2.5T today. Look and sound great, the installer fitted a 3" centre (no resonator) and 3" Y pipe. He had it idling when I got there, still on the hoist, sounded magnificent - can't wait until it becomes "carbonated" and gets a deeper note.

He reversed it out, and turned the engine off. I paid, I hopped in, started and drove. As usual, I immediately put it into S#. All good, the slight throttle through the carpark felt radically different, spooled up much quicker - immediately noticeable !! Maybe 400m+ of carpark, took 30 odd seconds, then stopped waiting for traffic for 13 seconds (yes it's timed on the ecu scanner, and yes I'm pedantic ). Now while I'm sitting there idling, it was sounding very rough. AFR and RPM all over the place - AFR jumping between 18 and 20, RPM as low as 560, high as 950, but basically hovering between 750 - 900. It's usually rock solid around 750. AFR usually sits at around 14.x at idle

Pulled out into traffic, went maybe 30 metres to traffic lights, lights turn red, and again started idling. Rough as guts again, same story with AFR and RPM. After maybe 10 or 20 seconds, I switched on AFR learning monitoring, to see what it was doing. It means nothing to me, but I know it would mean something to someone

AFR learning % is sitting about -7 at idle. Long story short, CEL is still on, AFR still sitting around 18 at idle. It's definitely down on power, although I haven't been pushing it too hard - worried I might damage something. Getting a backfire on change occasionally, although that is not unexpected, but it sort of sounds like it's overfuelling. I think.

I disconnected the battery for about 45 mins, long enough to reset the radio, but not the clock. CEL was still there. Took it for another drive, and no change to the (bad) behaviour.

I've disconnected the battery again, and will leave it overnight - but something tells me it's not going to recover.

A couple of other observations - I turned on the monitoring of the rear O2 sensor, and it's getting a signal between 0 and and 0.97 volts. Not sure if that's normal or not, as I haven't recorded it before, so nothing to compare to. Also, my fuel economy appears to have improved greatly - but that might be because the ECU is retarding the performance. At idle it almost cuts out, and I can see the ECU applies a small amount of additional throttle to keep it going

So, fellow Liberty owners, any suggestions as to what might be causing it ????

Dwayne

[gtspec]

hmm interesting post, subscribed

i still have problems with my CEL light after i changed DP and exhausts but put it down to the tune and sensors not liking the extra air flow.. i have been this way for a few months now and going to correct the problem by retuning..

i also had the problem of the idle movement but managed to keep that under control by tighting my aftermarket blow off value air pressure.. if you have an aftermarket BOV i would suggest maybe doing the same or changing back to stock until you can figure it out..

[senator]

strange, currently running phat dp, phat centre and cans...... so far so good, its driven daily in traffic and even done a track day, with no issues, not even a backfire,

Have you logged your boost since getting the tbe fitted? i noticed mine peaked a little higher.

[SillySora]

Hmm i have had same sort of things with my lib.

What ecu do you have.
My tuner said that when he was tuning my car those error lights kept coming up, so he turned them off cause the car is tuned to be safe .

However said that if they do return disconnect the battery and let it idel for 1 minute then see. If they are still their call him. Haven't had to do that yet.

Also like to add when I did get on the gas one time just chucked a major fit at me do much air or something on came the lights. Turned it off was ok by next day haven't had them come back.

Hope my dribble helped at all. Dam stupid computers i put it down too.

[GTSPECB STI]

shit subaru stock tune and massive reduction in back pressure will be the reason Dwayne. Get her booked in with Sean asap and your problem will be solved.

[CheesyMong]

shit subaru stock tune and massive reduction in back pressure will be the reason Dwayne. Get her booked in with Sean asap and your problem will be solved.

Agreed those are big changes to the car it desperatley will need a tune, the stock settings for the AFR can be terribly dangerous that should be sitting in the 11-12 range when on power.

2nd the VERSO

Cheers

Joel

[GTBR46]

Noteto self:

Dont fit a centre pipe until I am ready to have it tuned.

I have DP, and quads, stock centre, runs perfect.

[Arith]

Dwayne, did you say your Y-pipe is 3" as well? Is that just the initial part and then it's split into smaller piping? Or are you running 3" in the split pipe as well? Because the Phat mufflers only run 2.5" for the inlet pipe.

[Boxer]

Perfectly expected to have CEL's after such a change. Most likely the error will be Cat efficiency outside expected values (one sensor before and one after the Cat measure this). Also With fitting a large exhaust the turbo will spool much differently in regards to ramp up, flow). The ECU will take a bit to learn this and its not adviseable to flog it during this period (S# was never used on my car anyway, but it means that even hlaf pedal was almost full throttle on an ECU trying to learn new parameters and keep boost spikes at bay) Hence why everyone is telling you to get a tune - its the only way to make the most of the zorst, and then a decent tuner will expand the expected range of the O2 sensor measurements to eliminate annoying CEL's

Likely you did see some decent boost spikes, and perhaps a det or two.

Not sure why it would be running so badly though even after disconnecting the battery - the ECU should have pulled everything back. Have you checked your intercooler plumbing and the airflow meter plug? The intercooler has to come off to fit a new DP (well most shops do it)

Need to pull the CEL code before going much further than that - wont the Datascan do this for you?

[blacknwhite]

I have got the full Phat treatment and still to have a tune as still got a couple things to do, and have had no issue
Total Noob but would it have anything to do with no res in the centre pipe???
Phats centre ,for mine anyway had one , maybe that little bit more freedom is pushing it over the parameters of the factory tune
Feel free boffins to point out if talking rubbish, which probably am!

[dwayne]

Wow, thanks for all the replies and suggestions guys - a couple of critical things I forgot to mention:
1) Apart from cosmetics & sway bar, car is completely stock, except for HKS panel filter.
2) It's booked inf or a tune on Thursday night

Jim, yeah sorry, Y pipe goes down to 2.5" to connect to Phat quads


Cheers

Dwayne

[senator]

Dwayne, did your Ecudatascan log the fault? and were you able to clear it?

[PHAT GT]

the reasion your car runs rough is there is a hose of somwhere or a air leak somwhere

there has been over 35 of these dumps fitted and most with aftermarket cat backs and ever time the cars not run right theres been a hose knocked of somwhere while fitting the dump

Michael

[parso_rex]

Perfectly expected to have CEL's after such a change. Most likely the error will be Cat efficiency outside expected values (one sensor before and one after the Cat measure this). Also With fitting a large exhaust the turbo will spool much differently in regards to ramp up, flow). The ECU will take a bit to learn this and its not adviseable to flog it during this period (S# was never used on my car anyway, but it means that even hlaf pedal was almost full throttle on an ECU trying to learn new parameters and keep boost spikes at bay) Hence why everyone is telling you to get a tune - its the only way to make the most of the zorst, and then a decent tuner will expand the expected range of the O2 sensor measurements to eliminate annoying CEL's

Likely you did see some decent boost spikes, and perhaps a det or two.

Not sure why it would be running so badly though even after disconnecting the battery - the ECU should have pulled everything back. Have you checked your intercooler plumbing and the airflow meter plug? The intercooler has to come off to fit a new DP (well most shops do it)

Need to pull the CEL code before going much further than that - wont the Datascan do this for you?

P0171 & P0420 ?

[dwayne]

Dwayne, did your Ecudatascan log the fault? and were you able to clear it?

Diagnostics mode is separate to monitoring mode on the unit, and isn't working for Subaru's yet, which is one of the few drawbacks of the device.

Firmware updates coming to deal with it, just no ETA as yet.

Dwayne