My mr2 seems to have some major issues!
Only 204bhp at 18psi and was maxing out my AEM AFR at 10:1 (so easily could have been much lower)
And at idle it reads off the charts lean on my AEM 18:1+
I also have a code 21 and one of the previous owners cut the o2 sensor plug and spliced it all in.. im 95% they all make good contact etc but still issues persist.
My mods are
Gen2 Forged Engine on Gen3 management.
Decat & Blitz Nur Spec
BOV Delete
Upgraded SMIC
Cold air intake
MBC set to 13psi
540cc injectors (gen3)
CT20 Turbo
PLEASE HELP i am desperate and on the verge of giving up!
Super Rich on WOT and Super Lean on Idle
Forum rules
Many subjects will have been discussed before. Please try the search function before starting a new thread.
Check in the Know Your 2 as the information you need may already be there.
Important ! - Please make your topic title as descriptive as possible . titles with just "help" generally dont get as many answers as a title that points to the problem
Many subjects will have been discussed before. Please try the search function before starting a new thread.
Check in the Know Your 2 as the information you need may already be there.
Important ! - Please make your topic title as descriptive as possible . titles with just "help" generally dont get as many answers as a title that points to the problem
-
MR2T_Jake
Topic author - Posts: 59
- Joined: 21/12/20 8:27
- Years of MR2 Ownership: 1
- MR2's Owned: 1
- Real Name: Jake Le Port
- Gender: Male
- Location: Basildon, Essex
Super Rich on WOT and Super Lean on Idle
I can't figure out how to put in an image here, so this is my cry for help. 
-
MR2DI4
- Posts: 1474
- Joined: 20/04/11 23:18
- Current Model: None
- Years of MR2 Ownership: 23
- MR2's Owned: 1
- Real Name: 2023 i30N Hatch 6MT
- Gender: Male
- Location: Tauranga >>> New Zealand
- Been thanked: 1 time
- Contact:
Re: Super Rich on WOT and Super Lean on Idle
Sounds like a problem with the O2 sensor to me, pays to replace it with the correct part that comes with the correct plug, you shouldn't have to splice it in.
Basically with the car sitting there and warmed up the AFR should show 14.7:1 with maybe tiny oscillations and thats with the old narrow band sensor so the Gen 3 wideband should be even more stable.
If its not right at idle then its not going to be right anywhere. Idle is the easiest for the engine management to cope with.
Just ran mine, it takes about 5 minutes for the O2 sensor to get hot enough to start working. AFR gauge reads 15.9:1 and gradually moves to 14.7:1 and just sits on this at idle.
Not sure if the stock gen 3 engine is a straight wideband or if it has a heater in it as well, probably pre-heater so its only a 3 wire instead of like a 5 wire.
Basically with the car sitting there and warmed up the AFR should show 14.7:1 with maybe tiny oscillations and thats with the old narrow band sensor so the Gen 3 wideband should be even more stable.
If its not right at idle then its not going to be right anywhere. Idle is the easiest for the engine management to cope with.
Just ran mine, it takes about 5 minutes for the O2 sensor to get hot enough to start working. AFR gauge reads 15.9:1 and gradually moves to 14.7:1 and just sits on this at idle.
Not sure if the stock gen 3 engine is a straight wideband or if it has a heater in it as well, probably pre-heater so its only a 3 wire instead of like a 5 wire.
-
MR2T_Jake
Topic author - Posts: 59
- Joined: 21/12/20 8:27
- Years of MR2 Ownership: 1
- MR2's Owned: 1
- Real Name: Jake Le Port
- Gender: Male
- Location: Basildon, Essex
Re: Super Rich on WOT and Super Lean on Idle
Gen 3 o2 sensor uses 4 wires, 2 for heat, 2 for signal I believe.
I will have to splice in, as thanks to a previous owner I have no harness side plug!
I will have to splice in, as thanks to a previous owner I have no harness side plug!
I can't figure out how to put in an image here, so this is my cry for help.
-
SonicSW20
- Posts: 2858
- Joined: 29/11/10 19:50
- Years of MR2 Ownership: 10
- MR2's Owned: 3
- Location: UK
- Been thanked: 6 times
-
MR2T_Jake
Topic author - Posts: 59
- Joined: 21/12/20 8:27
- Years of MR2 Ownership: 1
- MR2's Owned: 1
- Real Name: Jake Le Port
- Gender: Male
- Location: Basildon, Essex
Re: Super Rich on WOT and Super Lean on Idle
Thank you. Still need to get to the bottom of my super rich boost and only 204bhp at 18psi (since lowered down to 15psi ish and probably will lower again to 13psi)
Please find my dyno graph below (so long as it works
)- 215210311_237131118036148_2885497595669443092_n.jpg (35.33 KiB) Viewed 93 times
I can't figure out how to put in an image here, so this is my cry for help.
-
MR2DI4
- Posts: 1474
- Joined: 20/04/11 23:18
- Current Model: None
- Years of MR2 Ownership: 23
- MR2's Owned: 1
- Real Name: 2023 i30N Hatch 6MT
- Gender: Male
- Location: Tauranga >>> New Zealand
- Been thanked: 1 time
- Contact:
Re: Super Rich on WOT and Super Lean on Idle
sort the o2 sensor it sounds to me it's not wired right or it's not working and the ECU is basically running in the default factory safe map. You have a fundamental problem there.
-
MR2T_Jake
Topic author - Posts: 59
- Joined: 21/12/20 8:27
- Years of MR2 Ownership: 1
- MR2's Owned: 1
- Real Name: Jake Le Port
- Gender: Male
- Location: Basildon, Essex
Re: Super Rich on WOT and Super Lean on Idle
New o2 sensor will be here tonight and i have got a generic 4 pin plug connectors to wire it all into, really hoping his helps and gives me my missing power!
I can't figure out how to put in an image here, so this is my cry for help.
-
MR2T_Jake
Topic author - Posts: 59
- Joined: 21/12/20 8:27
- Years of MR2 Ownership: 1
- MR2's Owned: 1
- Real Name: Jake Le Port
- Gender: Male
- Location: Basildon, Essex
Re: Super Rich on WOT and Super Lean on Idle
Update, I have replaced my o2 sensor which the original was actually wired in completely wrong! The signal from the sensor was going to a heater wire on the engine harness! The sensor was also rattly, so defo needed replacing!
Since installing the new sensor error code 21 & 25 have both gone and no error codes are being stored!
It seems to idle and drive pretty well now, however AFR gauge still reads max lean at idle! (i wonder if it cold be a leak in the downpipe to mid pipe where my exhaust restrictor is fitted... Restrictor is there to bring my boost down to a manageable level)
Cruising AFRs have gone from 12-13s to 14.7-16.5s which i believe to be much better, hopefully improve econemy too.
Any ideas etc from you guys is much appreciated, still don't think my power is up where it should be.
Since installing the new sensor error code 21 & 25 have both gone and no error codes are being stored!
It seems to idle and drive pretty well now, however AFR gauge still reads max lean at idle! (i wonder if it cold be a leak in the downpipe to mid pipe where my exhaust restrictor is fitted... Restrictor is there to bring my boost down to a manageable level)
Cruising AFRs have gone from 12-13s to 14.7-16.5s which i believe to be much better, hopefully improve econemy too.
Any ideas etc from you guys is much appreciated, still don't think my power is up where it should be.
I can't figure out how to put in an image here, so this is my cry for help.
-
gavsdavs
- Posts: 981
- Joined: 10/08/10 12:30
- Years of MR2 Ownership: 0
- MR2's Owned: 1
- Gender: Male
- Location: London
- Has thanked: 8 times
- Been thanked: 10 times
Re: Super Rich on WOT and Super Lean on Idle
It takes a while for the ECU to adjust to the updated parameters it's seeing from the sensor (i.. 100+ miles of driving). It sounds healthier anyway, any chance to redyno ?
-
MR2DI4
- Posts: 1474
- Joined: 20/04/11 23:18
- Current Model: None
- Years of MR2 Ownership: 23
- MR2's Owned: 1
- Real Name: 2023 i30N Hatch 6MT
- Gender: Male
- Location: Tauranga >>> New Zealand
- Been thanked: 1 time
- Contact:
Re: Super Rich on WOT and Super Lean on Idle
pull the fuse to the ECU or remove the battery connection to reset the ECU so it relearns
-
MR2T_Jake
Topic author - Posts: 59
- Joined: 21/12/20 8:27
- Years of MR2 Ownership: 1
- MR2's Owned: 1
- Real Name: Jake Le Port
- Gender: Male
- Location: Basildon, Essex
Re: Super Rich on WOT and Super Lean on Idle
Update all, Massive crack found in downpipe.... Sealed up with exhaust paste and idle AFR dropped to 14.7-15.3 at idle.
But after some driving is creeping up as the paste get brittle and breaks off. Should be all fine for a while as I await my TB Dev downpipe... Also need a CT20 turbo either standard rebuilt or Hybrid.
Cruising AFRs are now much closer to 14.7 than ever before! So hoping that improves fuel econ too! Thanks all for the advice!
But after some driving is creeping up as the paste get brittle and breaks off. Should be all fine for a while as I await my TB Dev downpipe... Also need a CT20 turbo either standard rebuilt or Hybrid.
Cruising AFRs are now much closer to 14.7 than ever before! So hoping that improves fuel econ too! Thanks all for the advice!
I can't figure out how to put in an image here, so this is my cry for help.
