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Hello all. I checked around but I couldn't find anything that matched my issues on other posts so forgive me if this is a repeat. This is my first post, and unfortunately it comes with a confusing problem. The car is a 2004 civic ex with about 160k on the dash. Completely stock, but the head gasket looked like it was blown (bubbles in radiator and smoke in exhaust). While I had it out I had a shop redeck the head and do a valve adjustment and cut new exhaust valve seats per their recommendation. Put it all back together and gave it back to my girlfriend, who owns the car. Ran decent for a couple of days but now the trouble starts. Car was performing poorly and feeling like it had no power, alongside feeling like it was slipping and hitting a rev limiter. It was misfiring running a p0340 and p0344. I brought it back to my house, replaced the cam sensor. No more misfire or fake rev limiter, but still poor poor performance and a fluttering noise (like a card in a bike wheel) in high rpm. It's throwing a P2a00 code but I'd rather not continue to throw parts at it. Sorry for my long post but I need to get this done ASAP. Thanks a bunch in advance

 
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PS. Car doesn't feel like it's shifting correctly either. Harsh shifts at weird rpms not consistent with how it was before.

 
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Did it jump time? (timing belt)

Did the timing belt tensioner drop its spring? (makes a whole bunch of rattles and lets the timing belt go slack and it can jump time)

P2A00 is an AF sensor performance code.....if you think it is causing running problems just unplug it (temporary) so the computer stays in open loop for testing, fix the other problem then see if the AF sensor code stays away

 
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I have not opened it up to check it. It just got a water pump/timing belt/tensioner spring all done by a local shop. Was running fine I wouldn't imagine the tensioner is the culprit. I will pull the covers off and check it tomorrow though I was hoping to get around going back into the engine but it seems I'm not getting off that easy. I will update tomorrow after I check. Would jumping time screw with my shifting though? The fact that I was shifting weird is what made me start thinking electrical instead of mechanical

 
Rep Power: 517

So take it back to the shop that did the work. Maybe they didn't get it right. You should have a warranty on the work done if the shop is halfway reputable.....but if YOU pulled the head off after a shop did this work all bets are off as to who might be responsible in the event of an error.

You only mentioned head gasket job and cam sensor in the first post...

How about cam gear bolt came loose? That might sound like a diesel engine rattling, but only for a short while LOL

Lots of possibilities. SOMEONE needs to figure it out so you can have real answers.
WAS fine.
Now it's not.
Imagining is not proof one way or the other.

And yes timing belt problem is possible, and if you would like to search you may find some spectacular stories of cheapo aftermarket tensioners having extremely premature failures that cost the users some piles of valves.

One that stands out in my mind:
https://www.civicforums.com/forums/3...-happened.html

There's also mention in that thread of a sensor bolt coming loose and causing lots of damage.

Depends on how it acts (not much description detail), but yes it sure can.
If the engine is suffering from a loss of power, the driver is gonna have to drive with the gas pedal down further than normal, and the trans sees that extra throttle input as hard acceleration (it can't understand the engine lost power) so it's gonna stay in low gears longer, maybe not shift until the engine hits redline if the throttle is open far enough.


Exhaust restriction/clogged cat?

 
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Yes sorry for the lack of info I didn't think it had any correlation to this problem but It went in the shop when she got the car for a small coolant leak that the shop ended up getting a radiator and water pump job out of her. 1200$ later and it's still acting up. So a couple weeks after that I get to work doing the head gasket. When I got the head back from the machine shop I did not check all of the bolts in there on the cam, so I cannot be certain that all of that is torqued to spec. To add as much clarification as I can on the shifting, low rpms seem fine. Once I pass about 2k it's has no power and when I go above 4k or so it makes a fluttering sound as described in the first post alongside the poor power. After I let off the pedal it will do a hard shift into the next gear. So my grocery list for tomorrow is to check the timing (I marked the belt to camshaft pulley with a white marker when I put it on last time so it should be easy) and timing belt tensioner. Pull valve cover to check bolts and nuts. Anything else I should get into while I'm down there? I'm not sure how I would check the exhaust past holding my hand against the end of the pipe to feel if exhaust was coming out. Anyways Thanks for the help I will update tomorrow with my findings

 
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that will not work,

that mark will not line up every time you spin the engine,

your cam might have to spin 500 times before that mark will line up again, that doesn't mean the timing is off,

you need to check the timing with the marks already supplied for you by honda on the crank and cam

 
Rep Power: 517

HahaNO.
God invented timing marks, and Honda put those marks of God on the engine so it can be set up and timed correctly by anyone with a service manual (and



I'm thinking this noise you describe is gonna be related to something loose, but I haven't heard it myself, all I can do is guess from here.
That's not accurate.

I could use a method called 'vacuum drop' (but if engine mechanical and running condition is not great this may not give accurate results), I could use my scanner to gain the same information from sensor data, or I could screw a pressure gauge into the port for the primary oxygen sensor and measure backpressure directly.



Oooooh. I've learned to recheck everything someone else touched before *I* install it.
Some guys in a machine shop might leave all the bolts they touch obviously not fully assembled so you know you have to finish it yourself, but others might not do the same....picture the guy putting the head back together spinning a bolt in finger tight but never tightened with a wrench (forgot?), now you installed it that way.

And hey, if the cam gear has been run with the bolt loose it may have beat the alignment dowel or keyway to hell....which means the camshaft would no longer be indexed to the gear correctly, causing timing error of the entire valvetrain. See how this can snowball?

Did you recheck valve clearances?

 
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I did not recheck valve clearances. I got the head back right at closing time and was in a hurry to get it back together. Seems that has come back to bite me on the *** with this whole thing. I have been helping a friend move all day and have not been able to look into the car. I'm about to start though so I will post on my findings. Really hoping that head was put together right otherwise this is gonna turn into one expensive lesson

 
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The Engine is in time. As soon as I figure out how to post pictures from my cell I will show you guys. But I pulled the crankshaft pulley off and the valve cover to get an exact look (as well as to double check the bolts on the cam and valves, they were fine). Sorry it took so long to get back, yesterday was hectic and I wasn't able to pull the car back apart. Now I'm lost though because the car being in time brings me back to square one

 
Rep Power: 517

Could the P2A00 code be related to the poor running condition, such as running very lean or something?

Is the exhaust restricted?

 
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How would you recommend I go about checking for restrictions? Could I just unhook infront of the cat and then unhook the headers and run compressed air through? Wouldn't it cause some type of misfire/backfire if it was restricted? I'm going to clean the fuel filters out tomorrow but I doubt it'll help, I just don't know if she ever had them replaced.

 
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Right. Stop there.
With the cat pipe disconnected from the header, take it out and drive it full throttle/full RPM to see if performance is greatly improved (in the RPM range you said it had no power).

Make sure the disconnected pipe cannot drag the ground or hit anything.
Disconnect sensors if the wires will get pulled on so you don't damage them.

Yeah it will be effin loud but you should know in a minute if it made a difference.