Newbie greetings and Impreza Lambda sensor question
Discussion
Happy New Year all. Just wanted to say hi as I'm a newbie to the Jap Chat section, and have a quick question I was wondering if anyone can help with.
I picked up a 51 plate bug eye Impreza a fortnight ago, which after doing about 600 miles over Christmas chucked up an engine warning light recently. Took it to an indy garage with diagnostics, which gave the error code as P0031 Heater Control Circuit - which apparently is the front 02/Lambda sensor.
Subaru quote £274
for a replacement - although Camskill supply a Denso one for about £150, which is what I'll be ordering! After a hideously expensive Christmas, I'm kind of wondering how hard replacing the part is at home, without any really decent tools, or if I can leave it until January's pay cheque at the end of the month without doing any long term damage? It looks like a real pain to get to! I only really use the car at weekends, but sometimes have to do a few longer trips.
Appreciate any thoughts, and all the best for 2010.
I picked up a 51 plate bug eye Impreza a fortnight ago, which after doing about 600 miles over Christmas chucked up an engine warning light recently. Took it to an indy garage with diagnostics, which gave the error code as P0031 Heater Control Circuit - which apparently is the front 02/Lambda sensor.
Subaru quote £274
for a replacement - although Camskill supply a Denso one for about £150, which is what I'll be ordering! After a hideously expensive Christmas, I'm kind of wondering how hard replacing the part is at home, without any really decent tools, or if I can leave it until January's pay cheque at the end of the month without doing any long term damage? It looks like a real pain to get to! I only really use the car at weekends, but sometimes have to do a few longer trips.Appreciate any thoughts, and all the best for 2010.
Hi, on the earlier MY00 cars, it's quite common for people to use a Halfords replacement sensor....sounds iffy, but if you do a search for it on Scoobynet, you'll see what I mean, and it was quite an accepted fix at the time. No mechanical difference from MY00 to yours, so no reason not to if they still stock them. Oh, and they're less than £50!
If the car is new to you, it's worth doing an ecu reset by disconnecting the battery for 10 mins....there was a well documented problem with the maf sensor gradually going out of spec, and leaning off the mixture, which is obviously a potentially costly issue on a turbocharged engine. Because it's a gradual thing, the ecu doesn't notice it, and it can go as far as holing a piston, or knocking out a big end. Do a reset, and check again for fault codes. You may find that the car immediately doesn't drive right after reconnecting the battery, which is in itself an indication that the maf was indeed out of spec. I've always regarded a knocklink as an abolutely essential addition to any high performance turbo, and have one on my current car. Scoobynet is your friend if you need a replacement maf, btw.
Don't mean to give you unnecessary reasons to worry, but better to know what to look for....I didn't have any such issues, but the tales of woe on the forum convinced me to regard the maf and lamda sensor as service items and replaced them regardless at 50k miles.
I loved my Scoob, and sold it under duress, so not slagging the car off at all, hope you enjoy it, cheers, Andy.
Don't mean to give you unnecessary reasons to worry, but better to know what to look for....I didn't have any such issues, but the tales of woe on the forum convinced me to regard the maf and lamda sensor as service items and replaced them regardless at 50k miles.
I loved my Scoob, and sold it under duress, so not slagging the car off at all, hope you enjoy it, cheers, Andy.
Heaveho said:
If the car is new to you, it's worth doing an ecu reset by disconnecting the battery for 10 mins....there was a well documented problem with the maf sensor gradually going out of spec, and leaning off the mixture, which is obviously a potentially costly issue on a turbocharged engine. Because it's a gradual thing, the ecu doesn't notice it, and it can go as far as holing a piston, or knocking out a big end. Do a reset, and check again for fault codes. You may find that the car immediately doesn't drive right after reconnecting the battery, which is in itself an indication that the maf was indeed out of spec. I've always regarded a knocklink as an abolutely essential addition to any high performance turbo, and have one on my current car. Scoobynet is your friend if you need a replacement maf, btw.
Don't mean to give you unnecessary reasons to worry, but better to know what to look for....I didn't have any such issues, but the tales of woe on the forum convinced me to regard the maf and lamda sensor as service items and replaced them regardless at 50k miles.
I loved my Scoob, and sold it under duress, so not slagging the car off at all, hope you enjoy it, cheers, Andy.
The ECU knows everything. The problem is that it can only go so far when making adjustments according to the ECU mapping. If the MAF is that far out the ECU cannot possibly compensate enough and eventually goes into limp mode and pulls timing/IAM when it eventually gets a very low or no MAF reading at all. Newage MAF's tend to go slowly and without throwing a DTC, unfortunately they don't often just give up and light your dash. A faulty lambda sensor though normally will throw a DTC and your car will run rougher than when the MAF has gone although it doesn't generally go into limp mode.Don't mean to give you unnecessary reasons to worry, but better to know what to look for....I didn't have any such issues, but the tales of woe on the forum convinced me to regard the maf and lamda sensor as service items and replaced them regardless at 50k miles.
I loved my Scoob, and sold it under duress, so not slagging the car off at all, hope you enjoy it, cheers, Andy.
As has been said a scoob engine running long term with a well buggered MAF is likely to have been experiencing low level detting long term without much warning if you don't know what you're looking/feeling for. It will eventually go bang on that last final rag down your favourite B road or on a Dyno power run when the engine reaches its highest loads.
You can kill a scoob engine even when it's gone into limp mode if you ignore it or you're too inexperienced or worse stupid to realise what's happened. I know someone this happened to and the engine rebuild was not cheap!!
ScoobieWRX said:
Heaveho said:
If the car is new to you, it's worth doing an ecu reset by disconnecting the battery for 10 mins....there was a well documented problem with the maf sensor gradually going out of spec, and leaning off the mixture, which is obviously a potentially costly issue on a turbocharged engine. Because it's a gradual thing, the ecu doesn't notice it, and it can go as far as holing a piston, or knocking out a big end. Do a reset, and check again for fault codes. You may find that the car immediately doesn't drive right after reconnecting the battery, which is in itself an indication that the maf was indeed out of spec. I've always regarded a knocklink as an abolutely essential addition to any high performance turbo, and have one on my current car. Scoobynet is your friend if you need a replacement maf, btw.
Don't mean to give you unnecessary reasons to worry, but better to know what to look for....I didn't have any such issues, but the tales of woe on the forum convinced me to regard the maf and lamda sensor as service items and replaced them regardless at 50k miles.
I loved my Scoob, and sold it under duress, so not slagging the car off at all, hope you enjoy it, cheers, Andy.
The ECU knows everything. The problem is that it can only go so far when making adjustments according to the ECU mapping. If the MAF is that far out the ECU cannot possibly compensate enough and eventually goes into limp mode and pulls timing/IAM when it eventually gets a very low or no MAF reading at all. Newage MAF's tend to go slowly and without throwing a DTC, unfortunately they don't often just give up and light your dash. A faulty lambda sensor though normally will throw a DTC and your car will run rougher than when the MAF has gone although it doesn't generally go into limp mode.Don't mean to give you unnecessary reasons to worry, but better to know what to look for....I didn't have any such issues, but the tales of woe on the forum convinced me to regard the maf and lamda sensor as service items and replaced them regardless at 50k miles.
I loved my Scoob, and sold it under duress, so not slagging the car off at all, hope you enjoy it, cheers, Andy.
As has been said a scoob engine running long term with a well buggered MAF is likely to have been experiencing low level detting long term without much warning if you don't know what you're looking/feeling for. It will eventually go bang on that last final rag down your favourite B road or on a Dyno power run when the engine reaches its highest loads.
You can kill a scoob engine even when it's gone into limp mode if you ignore it or you're too inexperienced or worse stupid to realise what's happened. I know someone this happened to and the engine rebuild was not cheap!!
I really hope it's not the MAF. According to the diagnostics at the first garage I took it to when I was away at Christmas, apparently the fault code pointed to the front Lambda sensor. The car appears to be 'normal' - at least from what I can tell- in every other respect. Still pulls well, although I'm not thrashing it, doesn't miss or idle rough. I've only been putting it off due to the cost of the replacement Lambda.
I've booked it into a garage next week, as on balance,
although it'll probably be crippling, I'd rather someone who knows what they're doing has a look at it.
Thanks again for the advice.
The MAF went over time (we believe) on my classic turbo wagon and I didn't get any faults. Eventually it started to smell a bit oily and very soon it became very obvious something was wrong. A compression and leak down test pointed to a holed piston. I never experienced any particular roughness or bad running before we diagnosed the fault and it felt like it was pulling well (although the new engine immediately felt stronger). I replaced the engine with one from API and replaced the MAF at the same time. I'll put a new MAF on this year as a precautionary measure (2 years on and about 10k miles).
Later on the lambda sensor (new engine, same lambda) went out of normal range, the engine sensor light went on, recording a lambda sensor failure. As soon as the light came on th power dipped and it came back on. Fitting a new one from camskill cured this.
Later on the lambda sensor (new engine, same lambda) went out of normal range, the engine sensor light went on, recording a lambda sensor failure. As soon as the light came on th power dipped and it came back on. Fitting a new one from camskill cured this.
Edited by dern on Friday 8th January 19:05
dern said:
The MAF went over time (we believe) on my classic turbo wagon and I didn't get any faults. Eventually it started to smell a bit oily and very soon it became very obvious something was wrong. A compression and leak down test pointed to a holed piston. I never experienced any particular roughness or bad running before we diagnosed the fault and it felt like it was pulling well (although the new engine immediately felt stronger). I replaced the engine with one from API and replaced the MAF at the same time. I'll put a new MAF on this year as a precautionary measure (2 years on and about 10k miles).
Later on the lambda sensor (new engine, same lambda) went out of normal range, the engine sensor light went on, recording a lambda sensor failure. As soon as the light came on th power dipped and it came back on. Fitting a new one from camskill cured this.
Classic conclusion to a faulty maf unfortunately....in theory, before the engine actually gives up, the performance should get marginally stronger if anything, due to the leaner mixture. I was lucky/careful, and only got caught with the noisy 5th gear problem in the time I had a Scoob, no engine probs, thank God!Later on the lambda sensor (new engine, same lambda) went out of normal range, the engine sensor light went on, recording a lambda sensor failure. As soon as the light came on th power dipped and it came back on. Fitting a new one from camskill cured this.
Edited by dern on Friday 8th January 19:05
Heaveho said:
dern said:
The MAF went over time (we believe) on my classic turbo wagon and I didn't get any faults. Eventually it started to smell a bit oily and very soon it became very obvious something was wrong. A compression and leak down test pointed to a holed piston. I never experienced any particular roughness or bad running before we diagnosed the fault and it felt like it was pulling well (although the new engine immediately felt stronger). I replaced the engine with one from API and replaced the MAF at the same time. I'll put a new MAF on this year as a precautionary measure (2 years on and about 10k miles).
Later on the lambda sensor (new engine, same lambda) went out of normal range, the engine sensor light went on, recording a lambda sensor failure. As soon as the light came on th power dipped and it came back on. Fitting a new one from camskill cured this.
Classic conclusion to a faulty maf unfortunately....in theory, before the engine actually gives up, the performance should get marginally stronger if anything, due to the leaner mixture. I was lucky/careful, and only got caught with the noisy 5th gear problem in the time I had a Scoob, no engine probs, thank God!Later on the lambda sensor (new engine, same lambda) went out of normal range, the engine sensor light went on, recording a lambda sensor failure. As soon as the light came on th power dipped and it came back on. Fitting a new one from camskill cured this.
Replacing the engine wasn't so bad. The 'new' one was from camskill and they were extremely helpful in terms of advice. Sadly when fitted it pissed oil out of the crank oil seal but they had the car in and replaced the seal for me there and then and it's been great since. If anyone needs any bits like that I'd recommend them.
If you can get hold of the part number(I think its 226-41AA042),you can try here
https://www.chaplinssubarugenuineparts.com/index.p...
or here
http://www.o2sensor.co.uk/page002.html
PJ
https://www.chaplinssubarugenuineparts.com/index.p...
or here
http://www.o2sensor.co.uk/page002.html
PJ
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