Peroni

With a new air filter and a fill up of premium unleaded the fault has cleared! I realised that I had been driving extremely frugally (free-wheeling down hills, using high gears and a whiff of throttle) for over a hundred of miles, which may have triggered the error. I drove unti the cheap supermarket fuel my wife bought was all used up, fitted new air filter, filled it with premium and revved the engine hard through the gears for a long A-road drive. Check Engine light now off and has stayed off for a 300 mile round trip up north on the motorway. Car is driving much more smoothly on the new fuel too. The hesitation on part throttle is gone (although personally, I think the old carburettors gave a much nicer throttle response).

Thanks, Yeah, after I sell it, I will be running nothing except a 2012 Honda Jazz. We will see how that pans out. My previous Jazz was a 2005 model and was virtually maintenance free for nearly 10 years apart from corroding brake pipes, a known fault. Wish I'd kept it to be honest. I'd actually prefer an older model Forester, I far prefer the looks and field of vision of the older models, especially the pre-2006 ones. I never managed to find one without corrosion though (living in Glasgow doesn't help, lots of salty roads). I'll have a good visual inspection of the exhaust system when I get a chance and check any connections. I have no clue about the "steering angle sensor" didn't even know there was any such thing. I'd love a car with no computer some day; just carbs and electronic ignition (points ignition were crap).

Blinking’ hell! Out on a long run today and 20 miles in, driving to conserve fuel at a steady 40mph, the warning lights come on again. Interogating the fault codes using the trip button/lights on/off method throws this code: P0420 As a bonus, I also have: C0072 C0057 C0071 which are “body codes”? Im gutted to be honest, planning to sell the car next month, I’ve just spent £113 on the new sensor and now have a raft of other “faults” to investigate. I wonder what is causing the P0042 code and if it can be related to the previous problem and the new C codes? Can’t do anything about it right now, I’m the middle of a forest.

Finally got round to fitting the replacement sensor (Denso brand, via Ebay, £113). An easy job, for a change, since the old unit was not seized. Managed to get it off with a shifting spanner (I know, wrong tool for the job). Borrowed a 22mm spanner from neighbour to fit the replacement, along with his OBD 11 Scanner. I tried to test the old one before opening the package on the new one, but could not get any readings from any of the pins; open circuit across all pins with the unit unplugged. I was told to expect 5ohms across pins 3 & 4. Could be my multimeter though, wasn't sure I was reaching the metal connectors inside the block. Anyway , new unit fitted, battery re-connected and fault still showing. It took a "delete code" input with the OBD reader to make the fault go away. All sorted now. Thanks for the help folks, with special mention to Mr B.

Cheers Mr B. No other codes showing (the method in the video should be able to show multiple codes). I'll probably get one of the data cable thingies to be sure. O2 sensor heater...hmmm. Seems funny that would come on during a drive on a warm day. I'd have thought that would only be active on cold start up? I have a sense that the codes can't always be trusted 100%, although they point in the general direction. I'll buy a Denso O2 sensor then if they are the legit ones. No point in scrimping and adding further gremlins to the system. Any tips for getting the old O2 sensor out safely? Are they tricky? It all looks quite clean around the sensor, can't see any rust.

Managed to get the fault code using this youtube video and the code is P0032. This seems to be an oxygen sensor related problem (not cheap!) so I shall investigate that route.

Driving along slowly on an "A" road, pulling my trailer, around 50mph and the Check Engine and Skid Control and Cruise warning lights all came on. Cruise light is flashing green which I guess means it is inoperable at present. I'm wondering what this could be? I hope it's simply a sensor getting an out-of-range reading and deciding to throw an error and not something ghastly and expensive. Car is an 2010 2.0 litre X Petrol, manual with 80,000 miles on it. Does anyone have an idea what could cause this and how to investigate and/or fix it cheaply? I need to save money because covid has wrecked my business. Car does not seem to be lacking in performance, but hard to tell with a 600kg trailer on tow. No other issues apparent, ticks over and sounds the same as usual. Help!

Thank you for the detailed guide. Apologies for the very slow reply!

Good idea! I might just do that. What goes in between the flanges? Is it some kind of compression gasket? And the bolts are just called "exhaust flange bolts" with springs, or something?

Thanks for the Ebay link Mr B. Yes, those flanged repair sections looks a better solution that the flexi bolt-on stuff. ( I always wonder if those exhaust clamp things attract corrosion and speed up rot)

I'd kind of hoped that by turning up at the exhaust place this morning, with the car, that they might just take a quick look at it and decide it was a 30-min job. No such luck, they are snowed under and the chap seemed quite stressed out. It's booked in for 8th March, earliest I could get. An unpleasant couple of hours stretching under the car with angle grinder and reciprocating saw etc. Here's what I ended up with; I cut off the rotted flange from front pipe and the small reducer part I had bought was a decent fit to both pipes. So, rather than fit the flexi S/S section ( which I might still do later) I just sleeved both pipes with the reducer, using some stove pipe fabric sealing tape and the exhaust sealer that came with the flexi kit. It all seems a good tight fit, but I'm a bit worried that it's not flexible enough to accommodate vibration & heat. We will see. Hopefully this will last until the exhaust place can do a decent, professional repair with a new flange on the front pipe. The mid section seems in decent condition although the flange holes are a wee bit corroded. A rattle from the front pipe under the engine bay turned out to be a loose heat shield. I fitted new bolts to that, but it still feels like it will work loose again. It seems to only fix to itself. It's all sounding a lot quieter now. Strangely, I destroyed two brand new reciprocating saw blades cutting through the exhaust flange and bolts. Is it a particularly hard steel? Maybe my method was wrong and I overheated the blades by cutting at full speed? They were Makita branded blades, so I expected better. Thanks to all for the helpful advice. Especially Mr B. I was ready to cut the rear pipe's flange off without this advice.

Went back to exhaust repair place...they can't even look at car until 8th March! , so a home repair is on the cards. Only other places in town are Kwik-Fit and National Tyres who, I'm assuming will just want to replace with brand new parts (that I can't really afford right now). It seems a shame to slice up the middle section pipe/flange because it looks sound (on the right in picture below). It's the front pipe's flange ( left hand side) that has failed. I'll cut that off and see where that leaves me. Dunno why the spring bolts were tightened right up...surely that defeats their ability to accommodate expansion in the joint?

Thank you Mr B. I had kind of wondered about that issue. Rather annoying that I could not get down to my exhaust repair centre on Thursday to have them look at it. No doubt they would have recommended what you said. They seem to be geared up for repairs/fabrication and can source full S/S systems too. It is weeks between appointments there. I didn't know that a "pre cut flange" was a thing. I get what you are saying about having one side as standard and no doubt there are good engineering reasons for having that kind of sprung, doughnought, spherical joint flange thingy as standard. I have a 60mm - 54mm reducer. I could maybe use it to keep the side 60mm rear/centre pipe as standard by inserting it inside the "good" pipe. Bodging it until the pros can work on it properly. Can't quite think how to get a good seal though.

Sorry for my slow replies. I don't seem to get notifications any more. Thank you for all the suggestions. I wasn't able to get the car to the exhaust specialist today; had to cancel it because wife needed the car. Good advice re; not needing the whole front section. That would be a result! The front pipework looks OK from the rotted flange joint forwards, so hopefully a repair rather than a replacement. I have bought a "flexi pipe repair" kit from Amazon and will have a go fitting that on Saturday. I can't do welding. Only down side is that I will need to chop off the rotted front flange and also the perfectly good rear flange in order to fit the replacement part. It is stainless steel and from MIJ exhausts so should be decent quality. Another issue is that the front pipe is 54mm diameter and the rear/centre pipe is 60mm, so some bodging will need to take place. Jamie; I've seen replacement front pipes on Ebay, they are £667 though! (see pic below hopefully) This is the repair kit I bought from MIJ: Ebay, replacement front pipework: Found this picture on line but dunno if genuine part numbers or what?

My 2010, Petrol, Manual N/A Forester was diagnosed today as needing a new front exhaust section. The garage say its the section from the manifolds to the flexible joint (roughly underneath front seats). Garage suggested I try to find aftermarket part or get a custom stainless steel pipe made since the Subaru part would be "funny money". It has been blowing slightly for a while but getting worse of late. I had thought that it was just the join to the mid section needing replaced, since the joint looks crumbly. Was hoping that a bolt-on flex pipe would do the job. No such luck. I shall double check it myself tomorrow, just to be sure, and I have booked an inspection with a local exhaust repair/manufacturer place on Thursday. I'm beginning to worry this could be expensive. ( I've just forked out £250 for a wheel bearing replacement and £450 for 4 new tyres, so this has been a nasty post Christmas expense) Any advice? Should I try to source parts from a scrappy? How much work/labour is involved in replacing the front pipes? Will the cats and sensors being mucked about with trigger "check engine" warning lights? Should I do this work myself to save labour? ( No garage but I've decent tools and am quite handy although I hate working under the car outdoors)