Had the WRX a week now and already getting Subaru paranoia....some things probably not justified but some definitely are:

When I got the car (94 / 95 my WRX import with RCM 3" straight through exhaust, forge VTA DV, Polar piggyback ECU) the idle was wonky. I checked the stored codes and got CTS, so I replaced the sensor and then reset the ECU.

Ever since the ECU reset, I've had a problem with the boost in first gear.
Prior to the ECU, 1st gear boost was completely different to that of other gears, in that it came in smooth until a sudden punch in the back feeling at around 4500 rpm (guess), whereas all other gears were a more linear climb.

Now, since the ECU reset, if I try to accelerate through first, when I get to 4.5k or 5k rpm, it's as if the turbo stops for a second, as if it's died, then a bit of a backfire as it kicks back in for about 500 rpm upto say 6k (RPMS are rough estimates)

I'm mega worried about this, particularly with the undiagnosed rattle from the turbo area, which I haven't figured out if it's the turbo or the heatshield. This, coupled with the fact that I seem to have either a dodgy MAF or IACV, is making it hard for me to pinpoint the issue.

Anyone got any clues? Pleeeeaaassseee!!!!

 

Did you replace the ECU, or replace the faulty part?

 

Sorry mate, replaced the faulty CTS and reset the ECU to clear the fault code

 

Checked it this morning for clarification purposes. Seems to happen at 4k, and then sort of stutters and goes to 5k. All other gears boost fine.

Any ideas?

 

OK, so after a lot of reading it seems to be overboosting, but only since I did the ECU reset. It may be worth noting that I had taken some pipes off to replace the CTS prior to this occurring so I'm wondering if I have a leak somewhere, but surely this should affect the boost in every gear?

No matter how I drive it, first is a problem. It won't let me climb through the range gently or foot to the floor.

Anyone tell me if the boost solenoid could be to blame for this - and is it possible that this could rattle (have a rattle around the turbo area ) If so, where is / what is it?

Cheers

 

Try either refitting a standard DV or remove and blank off the Forge DV to see if it cures it.

What exactly is a 'Polar piggyback ECU'?




Can't see it overboosting in 1st @4-5k.

What does your boost gauge say, when the cut occures?

How much fuel have you got in the tank??


So most possibly not overboost.


You need to get that diagnosed asap.

 

Would cleaning the boost solenoid help (possibly?)

Will be cleaning my MAF today to see if it clears up the wonky idle a bit, if so I'll buy a new one.


Cheers mate, you seem genuinely helpful on here.

 

Think he means the Polar Performance Chip that Scott.t did a few years back... Pretty much what Major Sarcasm is selling now.

 

Just sprayed electrical contact cleaner on my maf, so hopefully that'll help a bit.

While I was there I checked all I'd undone on Saturday and found the hose under the intercooler which goes into the turbo was in place but jubilee clip wasn't tightened. Duh.

At work so not got chance to go try it out but could this have been the cause? Bearing in mind the problem only began when I changed the sensor?

 

It will not hurt, but i doubt it will solve your issues.


Thankyou very much. I try.

Yeah, i thought so. But i hate assuming.




Duh, indeed. Again, it will not of been helping your cause.

I don't know. But i'm sure you'll tell us either way later this afternoon.

 

Hold on to your hats then batman, be back at 5:30 with more tales of Impreza woe!

 

Defo try blocking your DV off and also check your sparks.

 

Haha!!!

Was due to the pipe not being tightened. What a retard! Still a slight little kick in the back in first mid boost but it's a good kick not a naughty one! (I hope)


My MAF cleaning has helped a little, hasn't tried to cut out once on the way home lol. It has dropped down to very low revs a couple times, but think this is pointing towards IACV now as after changing the CTS and cleaning the MAF the symptoms have got less and less severe.

IACV cleaning it is then!

As for the rattle - it's louder if I lay on the floor on the drivers side of the car than it is if I look at the the turbo from the top with the bonnet up. It sounds sort of like something rattling inside the exhaust. More investigation is required I think.


Cheers for you help guys!!!

 

Good.

Decatted RCM 3", not alot to rattle about inside that.

Get underneath it and have a bang around the on the exhaust. My money is still on the uppipe.

 

cheers mate!

 

All is now good with the boosting by the seems of things.

Still don't understand the whole IAM coutning thing, is there a info page anywhere?


This morning driving to work in the seriosuly bad rain on dual carriageway my CEL came on, checked the code and it is code 32. Intrigued by this as I have a decat. Someone said on another site it could be that something got wet and it's nothing to worry about, but I'd trust it more from someone more knowledgable here lol

Any clues?

 

Code 32 is the O2 sensor, or Lambda Sensor.

 

Have a decat so no lambda?

 

There will be a Lambda in the headers somewhere. IIRC there are two sensors.

 

Ok cool ta. This'll be fun. The engine light came on for about 3 minutes then went out. I'll clear the codes and monitor the situation for a bit I reckon.

 

Mosso is correct.

The cat on fire sensor is usually located in the downpipe. But has probably been removed.

You won't have to worry about monitoring the sensor, just watch your fuel gauge.

 

Haha ok.

Funnily enough, since the CTS change and an ecu reset, my fuel consumption has improved massively.

Last tank (sainsburys SUL 97) gave me approx 155 miles from full to quarter of a tank (3/4 of a tank!).

This tank (tesco 99) has done over 100 miles on just over a quarter of the tank. Who knows haha

 

What is the cat on fire sensor actually for? I have a decatted downpipe and i still have the sensor connected???

Matt

 

It's proper name is a 'Exhaust Gas Tempreture' (ETG) sensor. It, if fitted will throw a light on the dash if the gases get too hot, to prevent the cats cooking.



If you have no cats, there for nothing to cook.
I have a decat and the sensor removed (MY93 Classic), with no issues, you should be fine on a MY95. However, on a new age you would require either a resistor to fool the ECU or it can be deleted via a tweak to the map.

 

Thanks Bat, another great reply.

Matt

 

From my reading, I believe I have found the location of the o2 sensor. Apparently if I look under the front bumper on the drivers side, it should be there, and I can get a pattern one for 25 quid from Hellfrauds

 

Your navigation skills aren't too bad. It is located in the drivers side header (exhaust manifold). It can be seen either by sliding under the car or looking down between the OE airbox and the rocker cover.

I'm not sure how good or what brand the Halfrauds ones are, but i would/did buy one of these Bosch LS02's.
I did by a cheaper one at first but that only lasted for 100 miles.

Can you spot the difference??

 

[quote=b13bat;9718839] Your navigation skills aren't too bad. It is located in the drivers side header (exhaust manifold). It can be seen either by sliding under the car or looking down between the OE airbox and the rocker cover.

Now, heres a thing....when I look down here I see a heatshield. And on top of that heat shield, just happily laying there without a care in the world, is a black wire with what looks like a little metal connector (sort of like a bullet connector) on it.

hmmmmm

I'm not sure how good or what brand the Halfrauds ones are, but i would/did buy one of these Bosch LS02's.
I did by a cheaper one at first but that only lasted for 100 miles.

Can you spot the difference??

Is the top one the good one, bottom the cheapo?

 

When you buy the universal ones, they don't come with OE loom plug so you have to cut the loom and join the one black and two white wires with the (usually) supplied connectors. So, yes, could be.

Correct, the top one is the LS02.
As you can see, even the wiring is of better quality.

 

Cool, cheers for your help mate.

Will look at it more tomorrow!