First off, I DID use the search function, and found nothing i could relate too.


My 97, 4.6, 4x4 with 173k miles just had the stock manifolds replaced with Shorty headers. Aswell as a new EGR valve, and the tube that runs from the EGR to the header. After, it threw a code for Bank 2 lean (iirc) which i still havent gotten taken care of yet. As i do have the o2's, and am still running stock exhaust/cats.

Now recently, it has been running fine, then all of a sudden rpms drop, truck shakes violently and losses power. After a few seconds its back to normal and runs like a champ. I have done plugs, wires fuel filter, oil change all within the last 6 months (dont drive her alot in the summer either). I've had it happen twice while idling, and once while driving (uphill). The most recent time, it ran like stated above alot longer then before. Any ideas? Could it be related to the bad o2?

 

First try to clear out the obvious with a code reader. A code will point you toward it. Sounds like vacuum leak bringing about a lean condition. Possibly a hose or intake manifold gasket. Are you reading a O2 specific code?

 

The shop that worked on it (my dad works on their body shop side) has checked codes twice. And it was for the front o2 on the passenger side. Also cleared it 2-3 times. Still the same code. I did hear more of a "sucking air" noise after wards, but assumed it was normal since i couldnt hear much over the previous exhaust tick from my manifolds. I still notice a slight ticking, but dunno if its just usual noise or not. My other 97 with the same motor is hard to tell to compare since its straight piped.

 

Bank 2 lean is NOT indicative of a bad O2 sensor. Please post the exact numeric "P" codes.

 

Have the bad O2 been changed out?

 

IF i had a programmer/ scanner i would. I'll stop by again in the next day or two, and have it checked.

Not yet. If thats what it is.

 

Iac?

 

Usually lean coder mean a vacuum leak or CAI/tune condition. If you can check your I/M tests for completed or not completed tests?

 

Most parts stores will read codes free.

 

These would be..?

 

Been a few weeks, been super busy with work. Stopped by VAutoZone had them toss their scanner on it, it came up with P0133, P1131, P1132. Each code was shown twice for some reason aswell. As a reminder, i've had the EGR replaced along with the tube that runs from it down to the shorty headers. Also checked over all the hoses, and everything looks fine. No cracks or holes.

 

Those codes are for bank 1 and it seems that it cant see the 02 sensor so it says its confused. lean and rich,,,, 131=lean 132=rich

Along with the possible exhaust leak. Id go back an check all the egr connections too.

Also check the connections for the headers. You may need to replace the 02 for that

bank. First make sure you have no leaks in exhaust.

Dont the repalcement egr valves have a specific hole size you need to use for it???? Thru a washer????

 

I've checked all the EGR connections. I'll have to look closer to the headers, but from what i did check they seemed fine. I'm pretty sure i dont have an exhaust leak anywhere, i havent heard the noise to confirm one. But i am still runnin OEM exhaust from headers back. Not sure if that will create an issue either. As for the EGR hole size, no idea. Again, i had a shop do all the work for the headers as i didnt want to tackle it.

 

I am not sure myself. Ive seen it once on an egr valve,,,, when you replaced the orignal one with the new one,,, had several washers that had different size holes,, based on the number on the old one you used that washer that was assoiated by the manf.

good luck

 

Is your convertor clutch working correctly? If not it will cause idle problems? Best way to test it is to be doing 60 mph and lightly step on brake pedal it should release then about 4 seconds later re-apply.