comatosellama Posted October 9, 2018 Share Posted October 9, 2018 Just got word back from the dealer. I’ve got a bad catalytic converter, possibly bad rear o2, and am leaking oil from cam carrier, oil pump, and valve cover (just replaced valve covers, not sure what I did wrong). Car is worth around $5000, has newish (30k) head gaskets and clutch. 100% rust free which is unheard of in Michigan, and is already lifted. Dealer wants $4700ish, which isn’t gonna happen. My main issue was getting very low mileage, I can live with the car eating some oil. Right now I’m thinking I’ll get a tsudo hi flow cat and an o2 sensor and o2 sensor fooler since the high flow will trip the p0420. This should clear out the MPG issue. It doesn’t seem like fixing those leak points is too hard (I’ve done clutch work and a lot of stuff on my brat, I’m comfortable doing anything besides engine/trans internals). Do you guys think it’s worth it? My only real hesitation is the engine has a nasty piston slap. Thanks, CL Quote Link to comment Share on other sites More sharing options...
nvu Posted October 9, 2018 Share Posted October 9, 2018 Maybe excessive blowby and/or clogged pcv? Drive around and get the car up to temp, take off the oil cap and rev the engine a bit. If you see smoke coming out of the oil filler neck it's blowby. It's rare to see the oil pump seal leak. Quote Link to comment Share on other sites More sharing options...
comatosellama Posted October 9, 2018 Author Share Posted October 9, 2018 26 minutes ago, nvu said: Maybe excessive blowby and/or clogged pcv? Drive around and get the car up to temp, take off the oil cap and rev the engine a bit. If you see smoke coming out of the oil filler neck it's blowby. It's rare to see the oil pump seal leak. I’ve heard the increased back pressure from a clogged cat can cause blow by, hopefully a new cat system will help. PCV is new but isn’t a OEM. I’ll do that test once I get the car back. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted October 9, 2018 Share Posted October 9, 2018 No, don’t spend $5k on stuff that won’t fix the gas mileage concerns - diagnose/ fix bad gas mileage first. If that’s what matters - focus on that. $5k in repairs is absurd. get a new short block...lol If it’s rust free then it’s likely financially worth keeping - but there are many other important variables of choice. In 03, the rear O2 doesn’t impact gas mileage, it simply triggers the P0420 that’s it. I’ve ignored my 2002 P0420 for 150,000 miles and have had the same performance and good gas mileage for a decade. That is common, not rare fix the most important things first - P0420 should come right after buffing the underside of your trunk. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted October 9, 2018 Share Posted October 9, 2018 OEM PCV Are you condemning the converter on P0420 code only and bad gas mileage? That might not be what’s happening. Test the converter flow first? plugs, wires, adjust valves if you can. a leak down or compression test may help decide on engine condition. Quote Link to comment Share on other sites More sharing options...
el_freddo Posted October 9, 2018 Share Posted October 9, 2018 Oil pump leak is most likely the crank shaft seal - which means pulling the cam belt. It's a good time to replace the cam shaft seals too. dealer is probably quoting that obsurd price in the hope of a sale on anew vehicle. Cheers Bennie Quote Link to comment Share on other sites More sharing options...
comatosellama Posted October 9, 2018 Author Share Posted October 9, 2018 (edited) 8 hours ago, idosubaru said: OEM PCV Are you condemning the converter on P0420 code only and bad gas mileage? That might not be what’s happening. Test the converter flow first? plugs, wires, adjust valves if you can. a leak down or compression test may help decide on engine condition. I’m assuming that the cause of the mpg is the cat because that’s what they told me, and because Front o2, plugs and wires are all brand new. I don’t think that at 166k a new cat is an unreasonable thing to need 3 hours ago, el_freddo said: Oil pump leak is most likely the crank shaft seal - which means pulling the cam belt. It's a good time to replace the cam shaft seals too. dealer is probably quoting that obsurd price in the hope of a sale on anew vehicle. Cheers Bennie You think the dealer would get the location of the leaks wrong? Only went to the dealer so I could get the real answer. Somehow there aren’t any good Subaru shops around Ann Arbor. Edited October 9, 2018 by comatosellama Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted October 9, 2018 Share Posted October 9, 2018 (edited) find an independent shop to diagnose the car. P0420 is rarely a bad cat. conv. Some scary sounds are a weak timing belt tensioner and not rod knock or piston slap, etc. check you local Yelp and Angie's List, check your 'region' at www.NASIOC.com Edited October 9, 2018 by 1 Lucky Texan Quote Link to comment Share on other sites More sharing options...
montana tom Posted October 9, 2018 Share Posted October 9, 2018 Every time you are in a parking lot and you see a nice subi , ask where they get their work done. Sooner or later you will locate the hidden subi shop. There will be one somewhere. I know this because, I am the hidden subi shop around here. I get referrals all the time and I hear the same thing. OMG why didn't I find you sooner! Nobody else around here knows how to work on my Subaru ! Why don't you advertise??? Easy I don't need to. Quality Subaru work advertises itself ! 2 Quote Link to comment Share on other sites More sharing options...
comatosellama Posted October 9, 2018 Author Share Posted October 9, 2018 (edited) 1 hour ago, 1 Lucky Texan said: find an independent shop to diagnose the car. P0420 is rarely a bad cat. conv. Some scary sounds are a weak timing belt tensioner and not rod knock or piston slap, etc. check you local Yelp and Angie's List, check your 'region' at www.NASIOC.com I’ve already done the front o2 sensor (BOSCH), what else could be a cause of the code? Also, the car is getting 13-14mpg, seems like a normal p0420 doesn’t effect gas mileage. The head gaskets have been replaced and Ive heard that headgasket failure can sometimes ruin your cats. Going to question how the dealership on how they diagnosed the cat to be bad. Edited October 9, 2018 by comatosellama Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted October 9, 2018 Share Posted October 9, 2018 rear O2 could be bad, exhaust leaks will cause that code - just be SURE before spending $$$ for a cat. Quote Link to comment Share on other sites More sharing options...
brus brother Posted October 9, 2018 Share Posted October 9, 2018 they probably just diagnosed with the obd code. I have had p0420 on my 05 OB for the past 100K miles. No loss of power or gas mileage. I'll need HGs at the next TB interval. and maybe then install an aftermarket cat. Can't see throwing new original Subaru cat at the car with 210K miles I just clear the code and reset systems to pass inspections every two years. A clogged cat will reduce/eliminate power so if the medium is catastrophically degraded and blocking the exhaust it may reduce power. Once saw a car that plain wouldn't accelerate. Disconnected cat and it ran REAL loud but at least it got home. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted October 9, 2018 Share Posted October 9, 2018 13-14 mpg is terrible and has a root cause and is probably not the cat. Do some better diagnosis, asking the dealer what they did won’t help at this point. Describe driving conditions / you lay into the pedal, let car idle/warm up a lot, city driving? One friend of mine got 11mpg and complained and none of his trips for months was more than a mile or two. I made fun of him for complaining - sure mileage was bad but he’s filling up his tank like once every two months, boo hoo!! Are there any other check engine codes? check brakes - clean and grease slide pins with silglyde. Check pad retaining clips for bends or corrosion. Air filter, plugs, wires? Knock sensor - you should get a code but maybe it’s possible to have poor performance without a code? 1 Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted October 9, 2018 Share Posted October 9, 2018 yeah, live data or freezeframe data might be good here - fuel trims may be 'off' , or temp sensor bad, ,,,knock sensors can be cracked and will kill power , good suggestions above. Quote Link to comment Share on other sites More sharing options...
comatosellama Posted October 10, 2018 Author Share Posted October 10, 2018 8 hours ago, 1 Lucky Texan said: yeah, live data or freezeframe data might be good here - fuel trims may be 'off' , or temp sensor bad, ,,,knock sensors can be cracked and will kill power , good suggestions above. The cat was deemed bad through voltage readings at the dealer according to the guy. I’ve also done this and the front o2 was hovering around 1.5v, and rear fluctuated between .01 and .07 (or 0.7, can’t remember exactly, will redo test tomorrow) Im generally a little more throttle heavy than most, but as of recent have been trying to channel my inner grandma while driving. 5 days a week of 2-15 mile drives, kind of like your friend @idosubaru. 2 days a week I do around 70 miles on the highway. No leaks, just installed eBay headers and checked many times for leaks on them. This problem existed with stock headers. Also on tires 4.6% larger than stock. Just ordered o2 sensor (denso) and a cat (eastern). Won’t put on the cat until everything else is ruled out. Is a Bosch front o2 sensor okay? That’s what I’ve got right now. Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted October 10, 2018 Share Posted October 10, 2018 most folks avoid Bosch - Denso I think is OEM Quote Link to comment Share on other sites More sharing options...
comatosellama Posted October 10, 2018 Author Share Posted October 10, 2018 58 minutes ago, 1 Lucky Texan said: most folks avoid Bosch - Denso I think is OEM Thats what I’ve heard.. Sadly I believed rockautos OEM description of the Bosch Quote Link to comment Share on other sites More sharing options...
whynot Posted October 10, 2018 Share Posted October 10, 2018 every time I have had a cat cause issues, the car has always lacked power because the exhaust an not get out. The worst mileage change I ever had was due to a bad vacuum hose on the map sensor giving the computer bad readings. Trimmed the end, and back to normal. Took that car to 4 places and not one of them could fix it, until I found one of those hidden gems... (these were not subaru cars) I also think 160K for a cat is a short life time. All the failures I had were in the high 200-low 300K Find the cause of the MPG loss, and go from there. Quote Link to comment Share on other sites More sharing options...
comatosellama Posted October 10, 2018 Author Share Posted October 10, 2018 Power is a little low, but it’s not really any slower than my moms 2018 outback. I think I found a good shop at a recommendation from a local Ultimatesubaru member, planning on doing another round of diagnostics there, specifically for bad mpg this time. Probably will order a knock sensor since they’re so cheap. Quote Link to comment Share on other sites More sharing options...
comatosellama Posted October 11, 2018 Author Share Posted October 11, 2018 On 10/8/2018 at 9:52 PM, nvu said: Maybe excessive blowby and/or clogged pcv? Drive around and get the car up to temp, take off the oil cap and rev the engine a bit. If you see smoke coming out of the oil filler neck it's blowby. It's rare to see the oil pump seal leak. Just did my PCV and smoke started pouring out of the tube while I did it (car had been off for maybe 2 mins). Then opened the oil fill and smoke came out. No smoke when car is running though. Also found some oil drips: beneath cam Just to the drivers side of the crank pulley Quote Link to comment Share on other sites More sharing options...
nvu Posted October 11, 2018 Share Posted October 11, 2018 1 hour ago, comatosellama said: Just did my PCV and smoke started pouring out of the tube while I did it (car had been off for maybe 2 mins). Then opened the oil fill and smoke came out. No smoke when car is running though. Some smoke in that rear area is okay, that's what the pcv is supposed to remove while idling. With the engine hot, rev it aggressively couple times, as long is it's not spewing out a constant trail from the oil filler it should be ok. Was the old one clogged? Shake it, there should be a loud and metallic clack like a paint spray can. A dull thud would mean it's starting to clog up. You'll still have to address that oil leak, take off the cam covers. They should be 10mm bolts. Being that old and oil soaked, expect some nuts to be seized and end up breaking the plastic they're molded into. If that happens, just proceed with the rest of the bolts and pry the cover off. Only the side covers are removable, the center one can't be removed without taking off belts and crank pulley. Flashlight and phone camera can be used to inspect the center area. Quote Link to comment Share on other sites More sharing options...
comatosellama Posted October 12, 2018 Author Share Posted October 12, 2018 1 hour ago, nvu said: Some smoke in that rear area is okay, that's what the pcv is supposed to remove while idling. With the engine hot, rev it aggressively couple times, as long is it's not spewing out a constant trail from the oil filler it should be ok. Was the old one clogged? Shake it, there should be a loud and metallic clack like a paint spray can. A dull thud would mean it's starting to clog up. You'll still have to address that oil leak, take off the cam covers. They should be 10mm bolts. Being that old and oil soaked, expect some nuts to be seized and end up breaking the plastic they're molded into. If that happens, just proceed with the rest of the bolts and pry the cover off. Only the side covers are removable, the center one can't be removed without taking off belts and crank pulley. Flashlight and phone camera can be used to inspect the center area. Old PCV was making the right noises, but wasn’t OEM so I switched it to make sure it works 100%. Oil tube doesn’t smoke when I peg it. Also the car after fires a lot, not sure if that would have anything to do with all this. I’ll pull timing covers in the next few days and post the findings. I appreciate all the help!!!! Quote Link to comment Share on other sites More sharing options...
comatosellama Posted October 12, 2018 Author Share Posted October 12, 2018 Just did the cat and rear o2 sensor. Car drives much smoother now. Quicker to rev down and pulls a lot harder at low speed and high gear. Also sounds bad-rump roast when the silencer is out. I did noitice what seemed to be straight oil coming out of the tailpipe though, is this an indication of the valve guide seals going bad?? Quote Link to comment Share on other sites More sharing options...
comatosellama Posted October 13, 2018 Author Share Posted October 13, 2018 Cat and o2 seemed to be the fix. Did 120 miles on the highways today. No cel and roughly 25mpg!!! Just gotta get the oil to stay in the engine now Quote Link to comment Share on other sites More sharing options...
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