Please help, TB issues

[jonny985]

So I finally got an MAFT and decided to Port the TB. I have read all the posts regarding this and havn't had any luck yet.

I only took out the bottom half of the post, and installed a TB spacer I had it off. It is making a lot more power but I have some issues.

I was initally very pleased (knowing the initial results were expected) with the autotap readings around .95 on S1B1 .97 and S1B2 at idle; .94 on both while driving and about .85 at WOT. It idled ok, with a slight lope until it warmed up and then progressivly dissappeared.

My readings have gotten progressivly worse after leaning out the base 5% and richening WOT by 2%. The engine started loping very bad to the point of almost stalling. I went back to the computer controlling everything with no luck. My o2 readings are off the scale now and are hovering around 0 for normal driving and idle but are still giving me readings at WOT.

I also threw multiple trouble codes.
Misfire
Lean bank 1
Lean bank 2

Did I fry my O2 sensors with the rich condition?
If so, where do I find wide range O2 sensors?
Should I go to the 99+ sensor and romove the top of the post?

I reset the PCM last night and cleared all the codes but it didn't help.

What should I try next.

Any help is appreciated, I'm scared to drive my car like this and I was hoping to take it to the track tommorow morning with the great weather we are having here in the great state of MD.

[ November 29, 2002: Message edited by: jonny985 ]</p>

[jonny985]

I solved the loping issue after the car warms up but I am still getting some strange O2 readings, I'm going to make some more runs tommorow to see if they get any better.

[John_D.]

<blockquote>quote:</font><hr>Originally posted by jonny985:
...autotap readings around .95 on S1B1 .97 and S1B2 at idle; .94 on both while driving and about .85 at WOT. It idled ok, with a slight lope until it warmed up and then progressivly dissappeared.

My readings have gotten progressivly worse after leaning out the base 5% and richening WOT by 2%. The engine started loping very bad to the point of almost stalling. I went back to the computer controlling everything with no luck.

Did I fry my O2 sensors with the rich condition?

If so, where do I find wide range O2 sensors?

Should I go to the 99+ sensor and remove the top of the post?
<hr></blockquote>


The high readings at idle should only occur during cold start. Disregard those.

The o2's are supposed to sweep the range (at idle or part throttle) after the car is warmed up. The pcm does this on purpose, it even tracks how many times the o2's "cross-over" the midpoint and will throw a code if it is not flopping back and forth quickly enough.

The cross-over concept is like balancing a baseball bat standing up in the palm of your hand. If you hold your hand still, the bat will fall over. If you move your hand back and forth a little, you can balance the bat.

On mine, I finally realized that it takes a few (20-40) miles of driving for the pcm to adapt to maft base changes. That's probably why your car got progressively worse, it was adapting to the new setting the more you drove it. Also, going back to a zero base setting on the maft, will not kick in right away either. You'll have to drive it a while to let it settle in again.

Changes to the wot setting do take effect immediately.

Wide band o2 sensors won't be compatible with the pcm. They would report the wrong voltages as the pcm tried to sweep the range. They are good for short-term monitoring for tuning, but not for permanently replacing the stock sensors with. Your sensors are probably still ok.

You said you read the other "posts" (ha - a pun), so you probably took that metering plate off the back, right...? (just double checking)

If you can't get the maft dialed in right for the port, going with the '99 will smooth it back out. It won't be quite as good as the '98 unported, but it will be better. I mainly got into trouble with mine when I took the top half out.