Sorry this is so so long. But please read because I put a lot into it and I need the board's intelligent input!
I picked my car up today from having a week's worth of service to replace a long list of items (listed below). Upon driving home I noticed quite a difference in exhaust note. It was much deeper and throatier, and I could really hear the rhythm of the engine, like it sounds if you roll your r's. In the end, this may have seemed so different because I had been driving a Kia Rio rental all week (easter egg on wheels :grrrr
.
Trouble started once I got fast enough to get into 4th gear. At low rpm there is a lot of stuttering and between 3k-4k when gas pedal depressed it feels like there is no power being supplied by the engine. Just a minimal increase in acceleration, not the pull I am used to. So i started to get concerned. At one or two instances, right at 3k rpm the exhaust note dropped really deep for about one second and came back. That freaked me out a lot. I pulled over at a gas station to pull any fault codes (listed below). I then reset the codes.
After getting back on the road, everything seemed better. Exhaust sounded normal again, car pulled fine, I was happy
. Then I got to 4th gear and all the same problems remained. So I thought for a second, what had been done that could affect engine performance? Two things, cleaned throttle bodies which were very dirty as I was told, and installation of the Dinan big MAF housings. That's where I realized this could all be because of the larger MAF housings. I figured I would need a tune, and was going to get that done from Evolve when I get their headers. I had no idea it could make this much difference though! I read the fault codes when I got home too, after another 30-45 minutes of driving.
Question: Can the larger MAF housings be the issue I am having in 4th gear? 1st-3rd seem ok. If so, any real issue in running without modified software for a few weeks? I currently have the standard Alpha-N tune.
Also, please feel free to comment on the below figures for compression and leak testing, as well as on the pictures of my spark plugs.
Parts replaced
Water Pump, W/P pulley, T-stat, both Temp Sensors, belts, CPS x4, TPS x2, O2 sensors x4, Oil Change, cleaned TBs, Spark Plugs, Fuel Breather Valve, SAS cut-off valve, cleaned SAS tube of carbon buildup, all vacuum lines/hoses/o-rings related to these items and fuel pressure regulator, o-rings and gaskets for the heat exchanger, Dinan MAF housings, oh and the dipstick o-rings for good measure!
Codes pulled after initial drive - 1b 69 AA 6b 4E 78 77 E6 08 b2 b3 68 (I was getting 69 b2 b3 before the service)
Codes pulled after reset and drive- 1b 08 68 (much smaller list whew)
Code References
69 - Engine Coolant Temp, Plausibility (most likely resolved from t-stat change)
AA - Secondary Air System, Flow Too Low (hopefully fixed from valve replacement and tube clean out)
6b - Control Unit Self-Test, Pre Drive Check of Drive-by-wire System (no idea what this is??)
4E - Coolant Temp Sensor (hopefully just from replacing both sensors)
78 - Throttle Position Sensors, Cross Check (hopefully just from TPS replacement)
77 - Throttle Position Sensor 2 (same as above)
E6 - Drive-by-wire, Throttle Position Failure (same as above)
08 - NOT IN THE MANUAL ? (this one came back and worries me) :sad1: Could be "Intake CPS Cyl #5-8" in table 18
b2 - Catalyst System Efficiency Cyl #1-3 (these from before service, hopefully fixed)
b3 - Catalyst System Efficiency Cyl #4-6 (see above)
68 - NOT IN THE MANUAL ? (this one also worries me, it came back too) :sad1: I'll have to check and make sure this wasn't a "b8"
Results from Compression and Leak Testing
I was told that these are very good numbers, leak testing was 0% for all cylinders.
#1 - 218
#2 - 215
#3 - 220
#4 - 220
#5 - 216
#6 - 222
#7 - 218
#8 - 217
Spark Plugs (HIGH RES)
How do these look to everyone? I think these have about 30k miles on them.
I picked my car up today from having a week's worth of service to replace a long list of items (listed below). Upon driving home I noticed quite a difference in exhaust note. It was much deeper and throatier, and I could really hear the rhythm of the engine, like it sounds if you roll your r's. In the end, this may have seemed so different because I had been driving a Kia Rio rental all week (easter egg on wheels :grrrr
Trouble started once I got fast enough to get into 4th gear. At low rpm there is a lot of stuttering and between 3k-4k when gas pedal depressed it feels like there is no power being supplied by the engine. Just a minimal increase in acceleration, not the pull I am used to. So i started to get concerned. At one or two instances, right at 3k rpm the exhaust note dropped really deep for about one second and came back. That freaked me out a lot. I pulled over at a gas station to pull any fault codes (listed below). I then reset the codes.
After getting back on the road, everything seemed better. Exhaust sounded normal again, car pulled fine, I was happy
Question: Can the larger MAF housings be the issue I am having in 4th gear? 1st-3rd seem ok. If so, any real issue in running without modified software for a few weeks? I currently have the standard Alpha-N tune.
Also, please feel free to comment on the below figures for compression and leak testing, as well as on the pictures of my spark plugs.
Parts replaced
Water Pump, W/P pulley, T-stat, both Temp Sensors, belts, CPS x4, TPS x2, O2 sensors x4, Oil Change, cleaned TBs, Spark Plugs, Fuel Breather Valve, SAS cut-off valve, cleaned SAS tube of carbon buildup, all vacuum lines/hoses/o-rings related to these items and fuel pressure regulator, o-rings and gaskets for the heat exchanger, Dinan MAF housings, oh and the dipstick o-rings for good measure!
Codes pulled after initial drive - 1b 69 AA 6b 4E 78 77 E6 08 b2 b3 68 (I was getting 69 b2 b3 before the service)
Codes pulled after reset and drive- 1b 08 68 (much smaller list whew)
Code References
69 - Engine Coolant Temp, Plausibility (most likely resolved from t-stat change)
AA - Secondary Air System, Flow Too Low (hopefully fixed from valve replacement and tube clean out)
6b - Control Unit Self-Test, Pre Drive Check of Drive-by-wire System (no idea what this is??)
4E - Coolant Temp Sensor (hopefully just from replacing both sensors)
78 - Throttle Position Sensors, Cross Check (hopefully just from TPS replacement)
77 - Throttle Position Sensor 2 (same as above)
E6 - Drive-by-wire, Throttle Position Failure (same as above)
08 - NOT IN THE MANUAL ? (this one came back and worries me) :sad1: Could be "Intake CPS Cyl #5-8" in table 18
b2 - Catalyst System Efficiency Cyl #1-3 (these from before service, hopefully fixed)
b3 - Catalyst System Efficiency Cyl #4-6 (see above)
68 - NOT IN THE MANUAL ? (this one also worries me, it came back too) :sad1: I'll have to check and make sure this wasn't a "b8"
Results from Compression and Leak Testing
I was told that these are very good numbers, leak testing was 0% for all cylinders.
#1 - 218
#2 - 215
#3 - 220
#4 - 220
#5 - 216
#6 - 222
#7 - 218
#8 - 217
Spark Plugs (HIGH RES)
How do these look to everyone? I think these have about 30k miles on them.
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