4,000 rpm rev limiter

I have a 98 ex and recently installed a couple subs and amps. But the problem is, after the installation, my Accord wouldn't rev past 4,000 rpm (actually around 3,700-3,800). If feels like a rev limiter, and I have no idea what the problem is. The person who installed it for me even backtracked with me through every step he took. We're stumped.

And, yes, I searched. I do not believe my oil is low, but I am going to change it soon nonetheless. I do not have a CEL or any other light on. I read somewhere that my problem is caused by the engine being in "safe mode." Someone help please.

UPDATE

Sorry about being gone for so long. But I do have an update. I took your advice, Blacknight, and took my 6th gen to the dealer.

Long story short, it was my 2P connector or something. They did not find voltage from my 2P connector to my oil pressure switch. They repaired a wiring harness. Everything works fine now.

Of course, this was a couple of months ago.

Did you blow a fuse somewhere?

He checked the fuses and they were all good.

Thanks for the quick reply.

Sounds weird nothing to do with system but check your oil.

My oil seems normal, but I will be changing it within the next two weeks.

Any other suggestions? This is extremely annoying.

it might be your fuel pump, fuel filter. i fixed it before. my car used to bug out at 2 and a half. Took out the filter and cleanned it up, put it back together and now im reddddlining. yeah

this is purely a guess but you could try back tracking the power wire under the dash and in the engine bay to make sure it isnt in the way of anything or something was bumped and not on tightly. also make sure you amp power wire and fuse arent too close to the distributor cap- the current can jump but thatd probably blow the fuse for ur amps. my other guess would be to make sure the polarity is correct for ur amps (power wire isnt to ground).
you might need to reset the computer - disconnect the battery ground for 5 to 10 mins (you can hold down the brake for a lil while to speed up the discharge i believe) then hook it back up and see if it runs right again. but like i said, this is purely a guess, i really dont know.
hope you get it fixed

I'm going to try everything recommended in this thread, and I'll continue to search around for an answer. Most of what I've seen so far is oil related, but I don't know.

I'd greatly appreciate any other suggestions.

I found out it was a P1259 at Autozone.

I did some searching and found out the only things that I can really do it taking it to the dealer, changing the oil, or cleaning the gunk around the Vtec solenoid. I'm changing the oil soon, but I was wondering, what is this solenoid and how do I remove it to clean the stuff around it?

i had this exact problem the guys at honda said there wasnt enough oil to allow vtec to engage or somethin bout the oil pressure wasnt enough so all they did was fill it back up with oil and problem fixed