Question about 1996 Subaru Impreza

1 Answer

High co2 from exhaust Failing MOT. Subaru impreza 96 have put new exhaust downpipe on, it has noo cat on it, any suggestions!

Posted by on


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Master
  • 518 Answers

The cat has the ability to reduce the co2 levels ,so it needs the cat to pass the mot

Posted on Jul 07, 2010

Testimonial: "very helpfull and fast responce"


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Hi , I have a subaru impreza 2009 with a po137 code I replaced ox 2 sensor banck 1 , reset the code but still coming back...any suggestion?

code p 0137 refers to heated oxygen sensor (HO2S) 2 bank 1---low voltage ===causes --exhaust leak---wiring short to ground---HO2S --ECM
it also refers to oxygen sensor(O2S) 2 bank 1--low voltage ===causes exhaust leak---wiring short to ground--O2S-- ECM
HO2S sensors are in the exhaust manifold before the cat converter and O2S are in the pipe after the cat converter there is a flex section of exhaust pipe covered by a stainless steel mesh and they crack under the mesh
I suspect that it is the HO2S that is faulty as it reports the gas composition of the exhaust gas so that the ECM can adjust the mixture

Feb 06, 2018 | Subaru Cars & Trucks

1 Answer

Car has failed mot on high co2 emmisions

Have you had the ECM checked?

The ECM controls your fuel to air mixture as well as monitoring the CO2 levels.

Also, have you checked the oxygen sensor, when there's too much oxygen intake,,, the ECM increases fuel to compensate for the excess air, and thus results in more CO2.

Another check would be to find the diagnostic port, (usually under the dashboard), and, to either hire, or borrow an OBD diagnostic tool and see if there is an error code displayed, beginning with 'P', the code will show you what component is likely to be in error for producing the high CO2.

Jun 11, 2014 | 1998 Kia Sportage

1 Answer

High CO emissions. MOT failure. No codes. Runs like a dream. Fuel consumption high

check that the cat converter is not failing and blocking up the exhaust system. or not doing it,s job. replace both HO2S and O2 sensors

Apr 15, 2014 | 1999 Land Rover Range Rover

1 Answer

91 chev pk up high co2 at idle

retest could be a contaminated gas anilizer high co2 isnt a bad thing it means teh cat is working high CO is a failing cat whats the hydrocarbons at

Mar 11, 2014 | 1992 Dodge Stealth

1 Answer

Hi, i have subaru impreza 1.6L for almost 2 years. I have a acceleration problem which come and go... (not permanent) The problem is when i try to accelerate it accelerate very slow(too slow), but if i...

well i do feel the dealer has milked the golden cow on this one ,engine flush and leads coil?? unnecessary money as far as iam concerned ,i suspect a particle filter on the exhaust system is causing the problem but iam not a subaru dealer mechanic so i do not know if its fitted with one like a peugeot but if it is then this would explain why on a run its ok as the filter will clear itself but short hops its clagging up now if it doesnt have a filter on teh back box then next thing is the cat ,so what you do is to buy a new cat then remove old one and knock the internal ceramics out of the old one and use it with nothing inside it as this will make it run ok ,then fit the correct cat when you take the vehicle for the test .

May 02, 2011 | 2006 Subaru Impreza

1 Answer

I have a 2004 wrx. Where are all the 02 sensors? I found the one by the catalytic converter but I don't know where the others are.

You have one right by the firewall. Its actually mounted on your downpipe by the turbocharger. and the other one is underneath the car on your exhaust. If you get under the car and look down the exhaust system you will see it plugged in.

Feb 20, 2011 | 2004 Subaru Impreza

1 Answer

I have a 1999 Subaru Impreza 2.2 Litre that is having power problems. Everytime we go up the hill, it seems to lose power. We just fixed the O2 censors and it is still losing power. Any ideas?

if not skipping and losing power take it to a reputible exhaust shop to check for exhaust flow.. possible stopped up cat. could also be a timing problem

Apr 10, 2010 | 1999 Subaru Impreza

1 Answer

What size is a 96 impreza 2.2 exhaust pipe

I think you will find it is 2.5 inches. The best exhaust to go for is a Haywood & Scott stainless system. Make sure you replace the downpipe . The design of the factory one is very restictive. You can then go for a 2.5 or 3 inch sustem. They sound wonderful . Also if you are there you might as well go for a set of GT Spec Headers. Unequal length to retail the Impreza burble.

Jul 01, 2009 | 1996 Subaru Impreza

2 Answers

2007 subaru impreza

for a subaru this can be a common problem and can cause the engine to stall or cut out my opinion is get a second opinion from a mechanic i will let you no cats can be very expensive depending on the type and cc of your vehicle

Sep 11, 2008 | 2007 Subaru Impreza Outback Sport Wagon

Not finding what you are looking for?
1996 Subaru Impreza Logo

Related Topics:

201 people viewed this question

Ask a Question

Usually answered in minutes!

Top Subaru Experts


Level 3 Expert

80531 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22326 Answers

Brandon Johnson
Brandon Johnson

Level 2 Expert

251 Answers

Are you a Subaru Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides