Lance Jardin

Hello! First time poster here

I have a 2005 Accord LX 2.4 5sp MT with 125k miles. Im having an odd issue that I cant seem to figure out without resorting to the old "replace parts and retest" method. I am an ASE certified master technician and this one has me stumped!

Problem: Above 5mph but below 25mph in 1st or 2nd gear under 1/4 throttle (got all that? lol) with A/C on there is an intense bucking that occurs seemingly at random, as it, itll go for 100ft, buck violently, I clutch in and it clears up, goes for another 150ft, buck again, clutch in again, clears up, etc... by buck I mean enough that at times, if I wasn't wearing my seat belt id probably be missing a few teeth, tire squeal and all!

Here's what ive done so far...
Scanned for DTCs, 1 present (for 5 years now, way before this problem) o2 sensor 2. No flashing MIL or new codes when symptoms occur.

Cleaned Throttle body
Cleaned MAF and MAP sensors
Cleaned VTEC solenoid screen
Replaced transmission fluid with OEM spec
Replaced sparkplugs
Ran 6 bottles of techron through the system over the course of 2 months


I know there's a lot more I can do but since being layed-off at the shop I was working at tools are limited. I guess im just hoping this is a common problem someone has the answer to so I dont go on a wild goose chase and drop lots of $$ for nothing. Thanks guys!

Lance Jardin

Also forgot to mention there has been a considerable loss of power in the last year or so (seat of the pants, 30-50hp). Dont know if its related or just the engine getting tired. Thanks again

johnsc2235

Could be a bad t body, or MAF sensor.. Try and get access to a scantool and look at the data list.. Look at what the tps and MAF readings are.

Lance Jardin

I have a scantool that plugs into my laptop. I'll try and see if it can check those sensors individually but I doubt it has an oscilloscope function like a Modis. Checked with the local NAPA and they can't even find a listing for the TPS (typical) but the MAF is only $60 so I may just end up replacing it for ***** and giggles. I'll post back once I've scanned it again

VeeSykkz

Replace the o2 sensor. it controls fuel mapping and could very easily be part of this problem. Youve known about the code for this long and havent done it.