Sorry in advance for posting another loss of power thread, but i'd like some specific advice from more experienced owners.

2004 6-mt
108k i've owned it since 80k

I've read most of the posts relating to power loss and pretty much pin-pointed the problem. I felt slight power loss and a rough idle.

After replacing plugs, coils, and wires. I went ahead and cleaned my SSV. Seafoamed through the intake manifold, cleared the memory, and cleaned the MAF sensor.

My car ran like NEW.

After about a month, the power loss came back and i'm here now. It runs better in the cold. SOMETIMES it decides to run better than normal which is weird to me.

Further reading makes me believe that I should check the cat and o2 sensors (I have a aftermarket exotic speed r1 exhaust). Also I've come to the conclusion that I should clean the ESS and fuel pump.

Any other ideas?
I plan on checking the coils, plugs and wires again. It sorta feels like its the SSV which makes me think the switch is bad or just sticking again. A compression check will let me know further information if my engine is failing.

I know this sounds like most other posts regarding power loss, but I want to have a thread giving me specific advice.

 

Have you made any recent unsavory modifications? Maybe an intake?

 

Only a racing beat revi duct. It's been on since I've owned it

 

I was planning on changing my starter to the upgraded one this weekend so that's when I will be diving into rechecking the ssv and plugs etc.

 

All your thoughts about your power loss issue are correct. Begin with these steps and start ruling out possibilities.

 

Pull down the front of the catalytic converter and see if it is plugged.

 

I'll keep you guys posted with further maintenance.

 

When you talk of a power loss, can you be more specific on how drastic of a loss it is?
It might help diagnose what the issue is or what is causing the issue.

 

It isn't anything too harsh. I can tell from my *** dyno that its a tad sluggish. It feels like a plug might not be firing correctly or my ssv is sticking. When I dive into my bay this weekend ill know more. My biggest dilemma is how it ran great after I replaced everything, then after a few weeks the power loss came back. My engine also has a repetitive chirping sound coming from it.

What are the symptoms of a vacuum leak?

 

Update: I cleaned my fuel pump (wasn't dirty at all) and installed the upgraded starter. I didn't have time to pull the cat or check my plugs, wires, and coils yet.

I still notice minimal power loss through full range of acceleration. I can feel my ssv engaging and it's safe to say either cat or plugs, wires, or coils.

 

If I was you, I would not push the car until I figure out what is causing the power loss. If your cat is clogged and you keep driving your car you might cause a bigger damage...Check your cat ASAP. In addition to pulling out the cat and visually inspecting it, you could also after driving hard for a while look underneath the car and check if the cat glows red (this needs to be done in a complete dark area). If it glows red your cat is done. Also do you hear any rattle by any chance that comes underneath your seat? If yes, you cat is bad.

 

I checked the cat and it was not clogged. Cleaned my plugs and inspected my wires and coils, all good.
It ended up the SSV being stuck again.
I'm probably just going to buy a new one because I recently cleaned it not even 3k miles ago and it shouldn't be sticking again so soon.

On a side note, after cleaning my fuel pump I think my fuel level sensor is being restricted from moving up and down. Sadly I didnt notice until I ran it out, which I can assume is terrible. Probably snagged on one of those wires in the fuel tank. Too much fuel in the tank now to check, i'll need to let it go down before inspecting it.

What does it look like?

 

If the chirping stops when you push the clutch in, then the clutch needs to be tightened. Mine was doing that.