TOPIC: 1999 Hyundai Accent 1.5L 5speed

This is an update on an existing post, one problem that was consistent during the time I was experimenting with the groove position on this vehicle was the inconsistencies with engine idle.

I have just completed replacing the MAF sensor and the Pre and post exhaust O2 sensors.

The idle issue has gone away and the engine is running much better overall.

Have a thread issue with the post sensor so for now there is an extenderin there until I can chase the thread out.

In the meantime, at idle...

Load_PCT... 2.7
SHRTFT1....-.8/1.6
LONGFT1.... -25 ( may be caused by the post sensor issue )
RPM........ 800
ETC........ 196F
TP%........ 8.2

@65mph
SHRTFT1.... -18.0
LONGFT1.... -18.4

I'll be taking this for emissions testing on Monday to renew the registration.

I have Pre-groove emissions results already.

Karl Fortner
Tacoma, Washington

Looks like ya did the right thing, Karl...If those FT#'s are accurate that is very good!

My own 85 Subaru has been running too rich with MPG going steadily down. No FT #'s of course. I replaced the O2 sensor yesterday that had over 50 K miles on it. I think it helped, the engine seems smoother and driveability is improved already. I disconnected both battery leads and jumper'ed 'em together w/ key and lights on.

Now it's acting more like it did right after I did the double Groove to it.
Good luck w/ the smog inspection, I would expect yours to do fine!

TracyG Gadgetman Reno

Something to keep in mind for O2 sensors, seems to be a common issue. That is why they make a O2 sensor thread chaser for less than $10.00.

Got one, used it and was able to put the sensor in without the extender.

Current fuel trims
SHRTFT1: -7.8 and varies through the spectrum
LONGFT1: 0.0 this does not change, I reset the ECU, restarted repeatedly, took it up on the highway... stays at 0.0
The SHRTFT1 on the other hand, as I said goes through the spectrum mostly negative numbers.. all the way to -25.0 depending on the driving.

Columbus day so no emissions check, will do that tomorrow.

Karl Fortner
Tacoma, Washington

Well, that was a bust...

Pierce County in Washington doesn't do "emissions" testing anymore...

They test your emissions system not the results of that system out the tailpipe.

Will have to go to a private shop since the "system" failed.

Catalyst: Not Ready
Evaporative System: Not Ready
Oxygen Sensor: Not Ready
Oxygen Sensor Heater: Not Ready

Hmmm

Karl Fortner
Tacoma, Washington

Wow that sucks, Karl!

So did they not like the physical condition of those 4 things? Evap system, something not connected right?

Catalyst- it's still there- is it lighting off? A cat has to hit 600 deg.F to light I think? Contamination from miles/fuel ratio can kill 'em. Check w/ infrared thermometer after say 10 min. of driving?

O2's- just replaced...?

What's going on w/ these? I've dealt w/ smog inspections for years, maybe your county has some new wacky inspection going on...OR--did you re-set your computer too soon before inspection? Some amount of drive cycles need to be logged after re-set before smog inspection w/OBDII, don't know exactly.

Well, buddy, keep us up to date, we always learn from whatever you are up to!

TracyG Gadgetman Reno

It's all computer readout, no looking under the hood or under the car for that matter.

I did reset the ECU very recently.

Guess I'm going to have to drive it around a bit to get it reconditioned.

According to the manual the O2 sensors kick in at 600F, guess the Cat would be functioning at that point. For that matter it would explain the LONGFT1 being 0.0

Later

Karl Fortner
Tacoma, Washington

Latest update,

Engine is running okay, definitely not getting the fuel mileage back but it looks like it is running strictly on the SHRTFT1 as the LONGFT1 is locked down at zero.

Looks like I'm going to have to replace the Primary CatCon on this puppy, still going to be a lot cheaper than replacing the vehicle.

Karl Fortner
Tacoma, Washington

Hey Karl, Captain Obvious here. Ya probably already knew, there are lots of Aftermarket cats around now, cheaper than OEM. Shop around if you have to replace.
Is yours blocked up? I learned in class yrs ago, thet need to get above I think 600 Deg F to light off check w/ Infrared thermometer.

TracyG Gadgetman Reno

Hi Tracy,

Yup, found one for under $200. The head temperature on the cat was over 600 but the overall temp was around 400. Figured something was going to happen at some point when the emissions were clean but the fuel mileage wasn't there.

Not a bad thing though, general condition of the engine itself is good. New MAF & O2 sensors, new CatCon and it should be good to go for another 100K miles.

Would probably run clean enough without the Cat but it won't pass inspection the way they are testing now.

Got a new Cat on order, should be here by next weekend.

Later

Karl Fortner
Tacoma, Washington