longun

First some info on the car. I've got a 2004 WRX wagon with a 2.5" turbo back classic system with the original 2nd O2 sensor fitted where the classic lambda would normally be, DoLuck panel filter, HRC fuel pump, PFR7B plugs (Gap @ .65) and a Bob Rawle remap.

The issue seems to have started when the exhaust was fitted but it may have always been there and is just more prominent since doing the above. In fact with each mod it feels like it's got worse.

The problem is a hesitation when coming back on throttle or at partial throttle, the car kangaroos. The other symptoms are the revs don't drop quickly enough during quick gear changes and it seriously pops and bangs when coasting in gear. It only does this in Closed loop. As soon as the throttle is applied or it goes near boost the car drives perfect and goes very well.

I've search and found tons on threads on here but no clear winners as what could be the cause. I have ECU explorer so can read sensor information from the car, is there anything I should be looking for? I can post logs if it helps anyone help me

So far in researching the issue the following could be possible causes.

MAF
Knock Sensor
Plugs
Coils
TPS
Lambda's
Air leak

In ECU explorer I am seeing knock correction of +2 to -4. I thinking of starting with the knock sensor but I've got no clue if those reading are normal or not. Also I'm still not sure if its a lean or rich issue in closed loop. The popping would indicate rich but most people have lean issues in closed loop.

If anyone else has had a similar issue can you let me know what cured your issue? Any other suggestions are welcomed

barnshaw

iTrader: (1)

out of interest do you run a VTA dump valve?

longun

No, running the standard recirc. I'm aware of the rich issues they can cause as metered air isn't sent back through the system.

But you've given me a thought. Most people with closed loop issues are lean issues mine appears to be rich, based on the popping/banging and slow to drop throttle during gear changes, maybe a should be looking for an air leak first.

For info resetting the ECU using ECU explorer seems to make it almost vanish, its still there but nowhere near as prominent. Then 5-10 miles later it seems to relearn the issue.

toneh

iTrader: (1)

Popping is not is not just a rich issue , ignition timing also plays a part and leaks
Also have you checked for exhaust leaks
Have you got your front 02 in the down pipe
Also Have you run learning view to check you're fuel corrections ?

longun

No exhaust leaks. The front O2 is still the standard item in the up pipe and the up pipe is still the standard item with the cat fitted. The second O2 that used to be post cat is now in the top of the down pipe as I'm running a classic system on a blobeye, it was cheap hence fitting a classic system.

Not run learning view. in fact I'd not heard of it before. Found it here: http://www.romraider.com/forum/topic2772.html will download and try during the Christmas break. Do you have any idea what I should be looking for or logging?

longun

Spoke to Bob Rawle. Great customer service he replied on Christmas Eve. The popping and banging is normal, although he can remove it I quite like it so I'll keep it. The revs holding on gear changes can be mapped out so I'm going to arrange going back to see him in the new year. This should cure the hesitation too. Should have just emailed him first. Will post up the Learning view logs anyway as it won't hurt.

toneh

iTrader: (1)

Have you fitted the exhaust and mods after bob mapped it ?