mhgleitz

I'm throwing a code 43. I've changed the fuel filter and the O2 sensor, but it hasn't fixed the problem. Also checked that the fuel pump is working and verified the cat wasn't clogged/bad.
Symptoms - Very poor gas mileage, Bogs down while driving (feels like it's flooding with gas) but only between 1-2k rpms and 3-4k rpms. Once it's above 4, it runs significantly better with only slight power loss.

History - I was changing the oil pan and checking the timing belt when this occured. I had removed the exhaust/header, unplugged the O2 sensor and removed the valve cover. Could one of these have caused this issue?

Also noticed while I was changing the oil pan that the spring from the tensioner on the timing belt had come off. It was still laying inside the plastic cover down near the pulley and looked like it had been there for quite some time.

However, I believe this only serves a function to set the tension on the belt before the nut is tightened on the tensioner itself. Besides, if the tension was loose on the timing belt, I'm pretty sure I'd be jumping teeth around the cams.

Can anyone help guide me in the right direction? I searched already, but everyone else seemed to solve their problem with the O2 or fuel filter.

Help is appreciated in advance. It's my daily driver and it's a big suck to drive right now.

Also should probably mention that I've reset the CPU numerous times. The CEL only comes on when I drive at rpms higher than 3K for at least 15 minutes.

However, it drives like crap all the time whether the engine is cold or hot.

xxmastermindxx

check this thread. that's what it sounds like to me.

mhgleitz

The thing that bugs me is that this started to happen immediately after I worked on the oil pan. What are the chances that the EGR would clog at the exact same time I did this work?

I'll go give this a shot. I'm willing to try anything that doesn't cost me another $170.

mhgleitz

Question... doesn't the EGR only function after the car is already warmed up?

I'm seeing this problem immediately after start up on a cold engine.

JasonST

The spring came off your tensioner? That can't be good... Check ur timing marks and make sure they still align to TDC. The problem you're having could definately be related to your timing being off.

mhgleitz

If I remove the valve cover and line up the camshafts at TDC, I should then be able to remove the rubber plug on the front of the block (near the tranny) and see a mark on the flywheel line up with an arrow.

Is this the correct way to check, or do I need to do this with a timing light?

vlang29

as long as the lock down nut holding the tension pulley was still tight, timing should be fine. That spring is used to set tension before tightening the lockdown bolt. But, it of course won't hurt to check..

when you are at 2-3 rpms and you floor it, does the hesitation stop?

mhgleitz

It's not as severe, but it's hard to tell because I go from 2 to 3k rpms in a short amount of time.

If I hold the throttle steady, then it acts normal between 2 and 3k rpms, then begins to bog down between 3 and 4 and then opens up after 4. I can do this with the engine unloaded in neutral or under load in gear, it doesn't seem to matter.

I checked the timing and the nut on the timing belt tensioner. Any other ideas?

vlang29

i know you said that you replaced the o2 sensor, but it sounds like you might have got a bad one... it has happened to me.. went through 3 in two months.

here is a good way to be 100% sure.

1) unplug the o2 sensor, right behind the oil fiter
2) reset the ecu
3) drive the car, see if the hesitation is any better
4) check your ECU codes again. You will for sure get code 41 for the o2 sensor, but if you don't get 43 again and the hesitation is better, it is most surely the o2 sensor.

mhgleitz

I tried this before I bought the O2 sensor. The code 43 went away and It threw a code 41 instead.

It still bogged down in the same rpm ranges.

mhgleitz

Bump for some help....

I played around with the timing today and advanced it a couple degrees. It's having a hard time idling without dying, however the bog-down now only happens between 3 and 3.5k rpms and it's not nearly as severe. Still throws code 43.

I put in some fuel injector cleaner, so after this tank we'll see if it makes a difference.

Any suggestions on other items I can check here?

mhgleitz

Does anyone believe this could be fuel pump related? Obviously the fuel pump functions, since the car will run.

I always heard that a fuel pump either worked or didn't work, nowhere in between. Is it possible for the fuel pump to be partially bad?

I've tried about everything I can try without blindly replacing parts. Any help is appreciated.

luderich_kid

i have the same problem, i just swapped in a jdm h22a but i used the usdm intake manifold, mine will intermittently bogged down in low rpms and the check engine light only comes on if i drive for a long time 15+MILES at hight speed. ive read a few threads were people readjusted their tps sensor and it fixed their problem. appearently they get knocked out of calibration. it looks like i bumped my tps when i installed the motor. haven't had a chance to check it because my voltmeter is down right now.
search tps! still not sure i understand the process of actually calibrating it though, could someone send us in the right direction for that