StingerLover
Active Member
After traveling for a week while my JB4 (and Densos) sat in the garage awaiting installation, I got to work a couple of hours after returning home.
I had read all 105 pages of the Hyundai/Kia thread on n54tech.com and just about everything here in advance.
After getting 5346 Densos gapped to .022" put in, I drove around a fair amount to see how the car was behaving. It may have been my imagination, but it seemed to run even better than before.
The JB4 install was easy, including feeding the OBD-II cable past the firewall grommet. After hooking everything up (except the fuel wires-for now), including the wireless connect kit, I first installed the v10 firmware. Updated without a problem.
I then started the car. I didn't explode and seemed to idle fine. Phew.
Next, I slowly pulled out of the driveway. I didn't make it far at all before the car was surging and jerking. Something was very wrong. Backed back into the driveway and garage. Double-checked all of the connections, removed the JB4 housing and inspected the wires, and disconnected the OBD-II cable.
Tried another very slow test drive. Same problem. Tried MAP 0. Sample problem. And I got a CEL and started to panic a bit.
After reconnecting the OBD-II cable, I got two codes from the mobile app, but both were P0000 no description.
I disconnected everything, restoring stock connections, and pulled the codes with a reader. P0108 and P0113, I believe. Cleared the codes.
Thankfully, the car ran fine after removing the JB4.
P0108 is a MAP error. The MAP connection seemed really snug when plugging in the stock connector to the JB4 female.
I gave the hookup another shot, but this time I twisted the wires on the JB4 harness and plugged the MAP connection in the other way, which went in much easier (like the TMAP connection on the front).
The car drove fine on MAP 0. Then it drove better (more power!) on MAP 1.
It seems that it let me hook up the MAP connector backwards on the first attempts. It could be my old eyes, but I saw no indication of which way it was supposed to go (there were tabs on both sides), and I had to turn the connector on the JB4 harness around to what seemed opposite to the way it wanted to go.
I've been running MAP 2 on 93 octane (10% ethanol) pump gas for the last two days and am loving it!
It definitely paid to keep trying.
I had read all 105 pages of the Hyundai/Kia thread on n54tech.com and just about everything here in advance.
After getting 5346 Densos gapped to .022" put in, I drove around a fair amount to see how the car was behaving. It may have been my imagination, but it seemed to run even better than before.
The JB4 install was easy, including feeding the OBD-II cable past the firewall grommet. After hooking everything up (except the fuel wires-for now), including the wireless connect kit, I first installed the v10 firmware. Updated without a problem.
I then started the car. I didn't explode and seemed to idle fine. Phew.
Next, I slowly pulled out of the driveway. I didn't make it far at all before the car was surging and jerking. Something was very wrong. Backed back into the driveway and garage. Double-checked all of the connections, removed the JB4 housing and inspected the wires, and disconnected the OBD-II cable.
Tried another very slow test drive. Same problem. Tried MAP 0. Sample problem. And I got a CEL and started to panic a bit.

After reconnecting the OBD-II cable, I got two codes from the mobile app, but both were P0000 no description.
I disconnected everything, restoring stock connections, and pulled the codes with a reader. P0108 and P0113, I believe. Cleared the codes.
Thankfully, the car ran fine after removing the JB4.
P0108 is a MAP error. The MAP connection seemed really snug when plugging in the stock connector to the JB4 female.
I gave the hookup another shot, but this time I twisted the wires on the JB4 harness and plugged the MAP connection in the other way, which went in much easier (like the TMAP connection on the front).
The car drove fine on MAP 0. Then it drove better (more power!) on MAP 1.
It seems that it let me hook up the MAP connector backwards on the first attempts. It could be my old eyes, but I saw no indication of which way it was supposed to go (there were tabs on both sides), and I had to turn the connector on the JB4 harness around to what seemed opposite to the way it wanted to go.
I've been running MAP 2 on 93 octane (10% ethanol) pump gas for the last two days and am loving it!
It definitely paid to keep trying.