Efsdn89

So I was driving my 06 Si coupe today, when I shifted into 3rd after coming around a corner, I felt a loss of power/choking, and noticed my check engine light came on as well as the battery symbol. I plugged in my scanner and found 4 codes p0102, maf sensor, p0340 cmp no pulse, p0141 heated o2, and when I ran it under Honda oem codes, found p1298 eld high voltage. The car won’t go passed 3,000 rpms. I cleared the codes and it said erase successful but the minute it rechecked for codes they were still there. I’ve done research on all the codes, but for all of them to go out simultaneously is just not plausible to me. So my question is, could that eld be bad, and would a faulty eld let the voltage spike thus taking out those sensors? I also checked my voltage at the battery with the car running and headlights on and my reading was 12.1v which is a bad alternator if you ask me. Has anyone had this issue before? Any insight would help. Much obliged.

ruddyrid

These cars tend to run the alternator at ~12v during idle, cruising and WOT. It's not until the system sees a load that it will bump up the voltage from the alternator.

I would start by checking all of your grounds though, and make sure you have good/solid ground connections. Here's a pic that gives you an idea where to look:

https://www.google.com/search?q=8th+...bVZuLZyB4rs9M:

rpared01

Check the ground cables as well