Welcome to the North American Subaru Impreza Owners Club Wednesday September 20, 2017
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
Go Back   NASIOC > NASIOC Technical > Normally Aspirated with bolt-on Forced Induction Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads. 
Thread Tools Display Modes
Old 04-01-2006, 08:46 PM   #1
Scooby Newbie
Member#: 31209
Join Date: Dec 2002
Location: Not really sure yet
2000 GC8

Default CEL Problems........... HELP!!

Hey Guys,

Haven't been on here in a while. hope everyone is doing well. Got a question to ask from the subaru gods, hope you guys might be able to help.

I've got a '00 2.5RS that's running a Ludespeed stage 1 kit (T3/T4OE trim I believe, don't remember to be honest). Well, the problem I've been having is the car has been throwing a CEL for a while now, had a custom exhaust on the car that ha just a 4" wide cat on the car (about 4" wide, about 9" long), so figured that was not much of a cat, so figured the cel was low cat efficiency. Well, finally took the car in to my mechanic, and he checke the codes and it turne out the CEL was a bad knock sensor and a bad front O2 sensor, nothing about the cat efficiency being low. So I had my mech change both the front and back O2 sensors (OEM sensors from dealer) and replace the knock sensor with a new one (OEM again).

So I drive the car for about 30 miles and get a CEL after about 30 miles. Take the car back in, now the car was saying "low cat efficiency". So I had the mech change for a new cat. Drove the car 30 miles again, cel again, took the car in again, same low cat efficiency code. So this time my mech put 2 cats on (a 4" wide by 9" long and a 3" wide by 9" long). Drove the car for 30 miles again, same cel goes off. So I take it in again, and my mech says it might be a ba O2 sensor, so he replaces my rear O2 sensor with the original one. This time I drive the car for 2 days and the CEL goes off after about 120 miles. So I take the car in again an he replaces the cats once again, but this time I notice that when he pulls the cats that were on to put the new ones on, the cats are basically black on the inside (like I swipe my finger on the inside of the cat wall on the exit end of the cat, and pulling out a finger full of chimeny soot). So I figure this is way too much for just 2 days worth, so either the car is running really rich or it's burning oil). Inspecting the car's exhaust, there is no blue smoke, (exhaust looks clear, no color to the exhaust gas). I pulled out the intake from the turbo, inspected the turbo blades, they spun freely with no problems and looked completely dry, so I don't believe it's a leaking turbo. Also inspected the intake piping going to the throttle body, looks dry. Inspected the spark plug wires, those looked fine except for a little oil on one of the wires, but not nearly enough for there to be that much oil being burnt by the system. I also check my oil level regularly, and haven't ever had to top up my oil between the every 3k mile oil change.

So now I'm thinking the car is running rich, and to be honest it might have always been running rich an I never noticed (fuel economy on the car has always been so-so after I put the ludespee kit on). So I'm thinking maybe it's a bad MAP sensor. But as far as I know, the MAP sensor was on the stock intake for the '00 RS, isnt it? So then, my question is, what is controlling the fuel for the car. Could the MAP sensor have been taken off the stock intake an put in the car?? Anyone with a ludespee kit know the details of where I'd even be able to find the MAP sensor in the car?? Or is it purely the Vortech FPR that's controlling all of the Fuel?? If that is the case, could a ba FPR be making the car run this rich?? Also for the entire week that I kept taking the car into my mechanic over and over again, whenever I was driving the car, I laid off the boost basically completey, So I believe the car is running rich at even idle an non-boost driving.

Anyone know where I can find the MAP sensor on the car and any other ideas??
* Registered users of the site do not see these ads.
brokemypiston is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 04-01-2006, 09:37 PM   #2
Scooby Newbie
Member#: 59353
Join Date: Apr 2004
Chapter/Region: Tri-State
Location: Alfred and Ithaca NY
2003 2.5 TS-Turbo
Pearl Ridge Blue


An idea would be to try and barow somones wideband 02 and check your AF?
psychochild is offline   Reply With Quote
Old 04-02-2006, 04:00 AM   #3
Scooby Newbie
Member#: 73288
Join Date: Oct 2004
Location: Wisconsin
2002 2.5 RS
Dark Blue


least your running rich.
v_dubs37 is offline   Reply With Quote
Old 04-02-2006, 10:39 PM   #4
Scooby Newbie
Member#: 9134
Join Date: Aug 2001
Chapter/Region: NWIC
Location: Seattle, WA
2000 Impreza RS-T
BRP w/Hydra+EJ257


Your low cat efficiency light is probably a P0420 Code if it is it means your cat is not heating up fast enough because of all the piping before the cat that you have now that you have a turbo. I have a stage 2 ludespeed kit and had the same problem, you get this problem too if you get aftermarket headers if your NA. Anyways you fix this by getting one of those CEL fixes that are out there. Its basically two resisters you splice into your rear O2 sensor that will correct this problem. I dont know how effective the mechanical CEL fixes are but the electrical fix solved my problems. It doesnt affect your performance at all its just a emissions thing.
Derk1127 is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Flashing CEL problem.. help! LuckyStar Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 40 06-18-2010 07:37 PM
CEL problems help (searched already) samuraiRS Normally Aspirated Powertrain 14 02-15-2010 09:11 PM
Perrin EBCS CEL problems, help? IIdiceII Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 8 04-02-2008 06:33 PM
Idling problems and wierd Cel problem.. Help please SPOOLME Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 4 01-26-2008 02:07 PM
CEL, weird boost, Big Problem- Help subarud Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 1 07-22-2002 08:28 PM

All times are GMT -4. The time now is 12:46 AM.

Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2017 Axivo Inc.
Copyright ©1999 - 2017, North American Subaru Impreza Owners Club, Inc.