praedet Posted September 24, 2011 Share Posted September 24, 2011 All right, so before I get into the details of the car or am asked about them, here is the basic premise. Car is modded, a good bit, and tuned for those mods. The car has run well for atleast a year with nothing ever really showing up in the LVs and the only thing I play withe is the summer to winter gas change. MAF learning is within +/-2-3% for A-D I changed the sparkplugs, the oil, and rotated the tires yesterday. When I started the car today, it is now idling really ROUGH and wants to stall (actually is stalling some). I got a cel saying bank 1 was too rich. The logging of AF Sensor +1 shows it pegged at 11.02 no matter what, open or closed loop. So, I reset the ECU and unplugged the front O2. After that, while the idling was still not ideal, the car runs fine with no knock at cruise or under boost. Sadly, i couldn't check the O2 readings with my LC-1 because it needs to be calibrated again or I can finally install the PLX wideband as the LC-1 is showing ridiculousness (varies between 6.02 under throttle to 20.22 when coasting with nothing in between) as well. Now, I think it is the front O2 going bad without throwing a cel. I have had it happen before and it is a consequence of Perrin Headers. But, I don't know that for sure and can't prove it yet. Any other possibilities anyone can think of? I am stumped:spin: Link to comment Share on other sites More sharing options...
Infamous1 Posted September 24, 2011 Share Posted September 24, 2011 I would inspect the front O2 sensor and also the plugs. Are you using one step colder as well? Link to comment Share on other sites More sharing options...
praedet Posted September 24, 2011 Author Share Posted September 24, 2011 Yeah, one step colder plugs that are brand new. I was using the exact same 1 step colder before... I have brand new stockers I could throw in to see what happens, but that is a LOT of work if it is a small possibility Link to comment Share on other sites More sharing options...
bnguyenbb6 Posted September 24, 2011 Share Posted September 24, 2011 Unplug your maf and see if it still does it. Link to comment Share on other sites More sharing options...
Infamous1 Posted September 24, 2011 Share Posted September 24, 2011 Unplug your maf and see if it still does it. +1 Also I have seen behavior like this before and it was related to the one step colder plugs. Link to comment Share on other sites More sharing options...
rao Posted September 24, 2011 Share Posted September 24, 2011 I thought one step colder plugs were required for any performance upgrades Rob IF YOU CARE ABOUT YOUR CAR YOU SHOULD NEVER DRIVE IT Link to comment Share on other sites More sharing options...
praedet Posted September 25, 2011 Author Share Posted September 25, 2011 Well, the injectors all measure 11.7 ohms with the car off, so they are probably not the problem. The O2 sensor will not be here till Monday. Should I really change the spark plugs to stockers before the O2 sensor gets here? Obviously that was something that I touched, but they are simply a new set of what was in there already... Link to comment Share on other sites More sharing options...
Spec B Posted September 25, 2011 Share Posted September 25, 2011 I would start by unplugging the maf and seeing how the car reacts. If it is able to maintain a good idle then you can pretty quickly eliminate the plugs as the issue. If it continues to run rough - I would then check the coils and change the plugs. It was the only thing you touched that could cause an idling issue. It is too much of a coincidence that right after the plug swap the issue came up. Good luck. Link to comment Share on other sites More sharing options...
praedet Posted September 25, 2011 Author Share Posted September 25, 2011 Well, plugging in the O2 and unplugging the MAF netted the following... Great Idle while the car was idling fast during warm-up. As idle came lower though, it got very rough again. The O2 sensor never read anything but 14.7. I thought it would come out of wake-up much sooner than it did. Revving the car at all with the MAF unplugged and the O2 plugged in made the car fall flat on its face. Too add to the fun, I did drive the car about 20 miles with the O2 unplugged, so if it wan't dead before, it could be now I have some time tomorrow that I can see about doing the plugs and putting in stock plugs. At this point I think the O2 sensor is gone as well even if it wasn't before Link to comment Share on other sites More sharing options...
hmmrdwn Posted September 25, 2011 Share Posted September 25, 2011 Installed plugs one time and the car didn't run well. Checked all the work and everything was fine. Pulled and reinstalled plugs and problem was still there. Took the car in and ended up getting a bad plug. Not saying this is your issue, but since you just did the plugs, I would focus on that work. Link to comment Share on other sites More sharing options...
praedet Posted September 25, 2011 Author Share Posted September 25, 2011 Yeah, I will be changing from the 1 step colder to stock today. At this point I believe the O2 is gone as well even if it wasn't before since I drove it for quite a ways with it unplugged. So, I will have that tomorrow and will get to try everything out then. I will probably see what it sounds like with just the changed plugs today if I get a chance... Link to comment Share on other sites More sharing options...
cryo Posted September 25, 2011 Share Posted September 25, 2011 Are you sure the coil boot seated all the way? If it started as soon as you changed the plugs I bet something like that will be your culprit. Make sure the gap is correct as well even though they are "pre gapped". I've seen people put a plug back on the shelf after it got smashed by a box of coolant, anything can happen.... Dave [sIGPIC][/sIGPIC] Providing unmatched customer service and a Premium level of Dyno/E-tuning to the Community cryotuneperformance@yahoo.com facebook.com/cryotuneperformance. Link to comment Share on other sites More sharing options...
praedet Posted September 25, 2011 Author Share Posted September 25, 2011 ^^^As sure as I can be My past experience is that if it isn't seated properly, you have to really force the bolt for the coilpack to even get it started. If it is aligned, it lines up to thread on immediately. Any easy way to check another way? I did check the gaps and all were great Link to comment Share on other sites More sharing options...
praedet Posted September 26, 2011 Author Share Posted September 26, 2011 Well, I didn't do what I said I was going to do... I changed the plugs to stockers (had to open up the gap a little on one) and did the O2 sensor. Everything is good now. I think the O2 was gradually failing rich based on the MAF learning. I will be adjusting the MAF scaling aver the next few days. Also put in the SM-AFR so I can now see the current AFR on a gauge as well... Thanks for everyone's help!!! Link to comment Share on other sites More sharing options...
cryo Posted September 26, 2011 Share Posted September 26, 2011 Glad to hear it was a simple fix. Dave [sIGPIC][/sIGPIC] Providing unmatched customer service and a Premium level of Dyno/E-tuning to the Community cryotuneperformance@yahoo.com facebook.com/cryotuneperformance. Link to comment Share on other sites More sharing options...
praedet Posted September 26, 2011 Author Share Posted September 26, 2011 Ha, yeah simple I am getting quicker at the sparkplugs Link to comment Share on other sites More sharing options...
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