Hey guys,

Long time lurker, first time poster here...

I have a 2006 civic si that occasionally sputters and dies on the road.

I used cobb access port on a stock tune to check the a/f ratio and it shows that my car is running lean, above 15 afr and rising under throttle.

I have recently replaced the o2 sensor as well.

My car also cannot engage in vtec and struggles to pass 4000 rpm,

it feels as if there is not enough fuel or the car is running out of gas.

My mods include a modified stock air box, kidd race header, tsx throttle body, and 2.5" exhaust.

I recently flushed the cooling system, perform an oil change, changed the spark plug, and cleaned the v-tech selonoid screen.

any help you guys could provide in helping me solve this issue would be greatly appreciated....

thanks!

 

What CELs are you getting? Is the oil level correct?

 

thank you for the reply.
No CEL or check engine light and the oil level is correct.

 

Sounds like it may be a fuel delivery problem.

 

Could it be bad ignition coil? any ideas?

 

I don't really think so as that would only affect one cylinder. You're looking for something that affect all the cylinders. Like fuel delivery problems.

EDIT: Are the plugs gaped correctly? Are you using NGK or DENSO? Hondas don't really like anything else.

 

Check fuel pressure

 

I think the car is running in safe mode and that is why it's not engaging into VTEC. It could a combinations of things.

Spark plugs properly gapped?
Could be also your tune isn't delivering enough fuel for the amount of air that is coming in.

You mentioned you changed the o2 sensor so we can scratch that out. I find it weird it's not throwing a code either. Can you disconnecting the battery for 10 minutes and then plugging it back in to make the ecu relearn the config. Let's see if that makes a difference.

 

Thank you for the reply.
I am currently on factory tune and modified
Stock air box.

So today i checked the spark plug and on cylinder 1 on the ignition coil i spotted some grease and it smells funny. So i replaced the ignition coil, reset the battere, drove it around the block, and when i try to pass 5k rpm the car feels like its hitting red line.

As for the spark plug i bought the set from autozone.. NGK iridium, but i don't know if its already properly gapped. Would spark plug gapped affect the vtec?
Thank you

 

Something is making your ecu go into limp mode which is not allowing you to use the car normally. This is done to save you from damaging the engine.

Usually the NGK Iridiums come pregapped so you should be ok for that.

 

Bad ecu??

 

Bump

 

If you want help post fuel pressure

 

^
Fuel pump or fuel filter?

 

Will do

 

Been 10 days... any updates?

Something this serious I'm surprised you haven't taken it into a shop.

 

I'm actually pretty curious to know what the issue is and if it's resolved!

 

#Update

Last week i replace one of the ignition coil on cylinder #1 because i spoted some grease and it smelt like fuel. Car drove like normal but still couldn't crack vtec.
One week went by and the car started to sputter again and no check engine light. So i decided to pull aside and call AAA to get my car toed to the nearest shop around.
While waiting for the toe truck i tried to reset the ecu back to stock tune (i am using COBB btw) and reset the ecu. Right after it says complete the left side of the dash where it says the temperature stoped working and the car wont cranked at all. Then i try to disconect the batere and try using my cobb to check any code but there's no conection at all to the ECU.
At this point i think i just fried my ECU. The shop cannot find any conection to the car ECU with thier OBDII scan tool. So now i might need to replace the ECU and get it reprogram.

 

Does anyone know how much would it cost for a brand new or used ECU for 06 si?? And how much would it cost to reprogram the ecu and the key?
Thank you

 

New, depending on where you get it, is $350-550. Salvage can be found for as low as $100 here: http://www.car-part.com/

 

I have a question regarding used ECU.. is theres any part number or anything that i have to be aware of before buying used ecu to properly work for my car?
Thank you

 

Once you get your ecu either new or used bring it a dealership to have them flash with your key. My buddy had to do it and the stealership didn't charge him anything but I'm not sure if in your area they would do the same!

Once you have it flashed by Honda try starting your car and see if VTEC kicks in if so then reflash it with Cobbs if it doesn't well something else is wrong.

Question why are you using Cobbs over Hondata?

 

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