P0432 and fuel injector flow rate

'00 with a stock 4.0 with CA Emissions. 150K. So I have been getting a P0432 code. Thinking cat but trying to rule out a couple things. One is fuel trims. I upgraded to 4 hole injectors and swapped out all 4 O2 sensors. The O2 sensors are NTKs'. The injectors are new. They have a flow rate of 250cc/min at 43.5PSI. Now my understanding is that stock injectors flow at 22.5lb/hr with a 49PSI. The best I can tell is that 250cc/min calculates to 23.8lbs/hr. Again this is at 43.5PSI. So with a pressure of 49PSI the flow is 25.3lb/hr. I used the calculator at the site below:

http://www.witchhunter.com/injectorcalc1.php

Does anybody see a problem here? Or any correlation between the higher flow rate and the P0432 code. The Jeep runs fine. Idles smoother, MPG have improved a little, and the butt dyno tells me she is a little peppier. By the way tailpipe is spotless as far as soot goes.

Whats the part number on the injector?

I did not go the traditional route. Bought them from a place local to me on the advice of a engine builder in my area. Bought from Marren Injectors. Part # 05942. I really do not think this is my problem concerning the P0432. Best I can tell with my little scanner is that fuel trims are within reason. A mechanic friend of mine was nice enough to check with his fancy Snap On scanner. Said everything seemed OK too. I am not going to pretend I understand fuel flow rates, and I am just assuming that all the specs above are correct, but since there is an increase of about 3lb/hr with a stock engine I started wondering.

I went through the Chrysler/jeep service bullitens none. The diagnosis steps say check that the o2 sensors are working correctly. If so replace cat converters. I've replaced plenty of these on the TJ Wranglers be they are similar

jeeptec said:

I went through the Chrysler/jeep service bullitens none. The diagnosis steps say check that the o2 sensors are working correctly. If so replace cat converters. I've replaced plenty of these on the TJ Wranglers be they are similar

Click to expand...

Best I can tell is that the O2 sensors, all new NTKs, are operating properly. Still might swap out the downstream rear. Might put the old one back in or defect the one in there and try another one. Would not be the first time a new part was defective out of the box. Again thinking cat but want to be sure.

Let us know what you find out when swapping back in the old O2 Sensor. I'd be it's your pre-cats causing the issue. I've been messing w/the same P0432 issue for a while and I'm finally getting the parts together to replace my Header/Exhuast Manifold and that d@mn Pre-Cat ... have the header sitting on my work bench in the garage but haven't decided yet which pre-cat to buy. Looks like a daunting task to replace them but I'll do what I can and hopefully get it all taken care of in the next week or 2.

Redsnake said:

Let us know what you find out when swapping back in the old O2 Sensor. I'd be it's your pre-cats causing the issue. I've been messing w/the same P0432 issue for a while and I'm finally getting the parts together to replace my Header/Exhuast Manifold and that d@mn Pre-Cat ... have the header sitting on my work bench in the garage but haven't decided yet which pre-cat to buy. Looks like a daunting task to replace them but I'll do what I can and hopefully get it all taken care of in the next week or 2.

Click to expand...

Will do. No idea when I will get to it though. Like I said earlier I am also thinking cat. Trying to rule out some of the other things that can cause a P0432. Exhaust leaks, vacuum leaks, fuel trims, etc. Thinking Walker when I do. Napa is running a $50 rebate on cats. Now is the time. Bet some of the other big box store might be too. Also Walker themselves maybe. Thing is there are 2 cats. The cheaper one for CA emissions vehicles not registered in CA. The the more expensive CalCat. Better warranty on the second one but about twice the price. Thinking might just bite the bullet for the CalCat. What did you buy for a header? Could you post a brand and part #? Just so happens I need a new muffler and tailpipe too. Seriously thinking about doing the whole exhaust. Plus I wonder if I have a small leak in there. I do here a little whistling. Thinking about just tearing everything apart. Replace the intake/exhaust gasket. Give my exhaust manifolds a good look for cracks. That is where the header might come in. Figure with all that out of the way it should not be too bad. Also thinking I might do motor mounts just because it will be wide open. Not thinking I have any problems with them but also have to assume that they are original. Really would like a header and a Borla exhaust but for a stock XJ? Seem like kind of a waste. Especially if my exhaust manifolds are OK.

I went w/the Rugged Ridge Stainless header

http://www.amazon.com/Rugged-Ridge-..._UL160_SR160,160_&refRID=0N7PGB51AB3J4PKJATE0

Just got the header in the mail yesterday and it appears to be very good quality. I haven't installed it yet so that opinion could change if there are fit issues.

And I also installed a Borla Muffler/exhaust ~ 1.5 years back that I purchased thru Amazon as well. Love the sound and quality and the price was nice when I bought it.

I also see the 2 types of Walker Pre-Cats... if they're both the same other than the CARB tag I'm going the cheaper route. I live in OK so no need to get it Cali certified. I've read bad things about the Walker precats... bad welds, incorrect O2 Sensor bung locations, etc... I just don't know which one to get as I want to get the correct part. I'll look into the Napa $50 certificate/rebate on them.

What model Jeep do you own? Seems to be conflicting info about this fitting an '00 XJ. I have seen this one but wonder about the one piece. Always kinda figured Mopar went to the 2 piece exhaust manifold to cut down on the flexing which I always assumed caused the cracks in '99 and down 4.0's. This is the Borla I have been eyeing. Is this the one you bought?

http://www.amazon.com/Borla-140071-...e&ref_=ox_sc_sfl_title_22&smid=A3W1EPXDEAW9MV

Even though these are for a TJ Wrangler 2000-2006 I wonder if these would fit. Borla part # 17202.

http://www.amazon.com/Borla-140071-...e&ref_=ox_sc_sfl_title_22&smid=A3W1EPXDEAW9MV

Pricey as hell but there are other 2 piece ones for TJ Wrangler 2000-2006's.

I own a 2001 XJ Cali Equipped Exhaust. Rugged Ridge's website says the headers I purchased w/fit all 00-01 XJs and some Wranglers.

That looks like the Borla exhaust I used. BTW... I think you linked the same part twice?? It was discounted when I got it at Amazon for ~ $380...

Yeah did sorry. Meant this:

http://www.borla.com/products/tj_wrangler_headers_part__17202.html

Also if my timing is good with a promo code I can pick up the Borla Cat Back Exhaust for that price too with a promo code on various websites.

Those look like headers a few people here have installed on their 00-01 XJs so you should be good w/those.

BTW... do you have a link for the $50 off from Napa? I've searched my local Napa's online store and they don't mention any discounts and I'd also have to order it from them. It's way cheaper to go thru Rockauto or Amazon for the same part.

Redsnake said:

Those look like headers a few people here have installed on their 00-01 XJs so you should be good w/those.

Click to expand...

I just like the idea of the 2 piece design. Wish I could confirm for sure if it is a straight bolt in using stock XJ parts after that. Problem is I would have to think that if it is they would advertise it as such and the '00 and '01 XJ's would be listed.

Redsnake said:

BTW... do you have a link for the $50 off from Napa? I've searched my local Napa's online store and they don't mention any discounts and I'd also have to order it from them. It's way cheaper to go thru Rockauto or Amazon for the same part.

Click to expand...

Can't find it on there site. But I know there is one because I am holding the form in my hand. They should have them in the store like mine does. Walker is also running one which might be better for you because I am guessing you can buy it anywhere and get the rebate.

http://www.walkerexhaust.com/promotions

I ended up ordering the Walker Cat thru rockauto and with the $50 Vida gift card it came out to be ~ $130 shipped. Hope it fits well.

Redsnake said:

I ended up ordering the Walker Cat thru rockauto and with the $50 Vida gift card it came out to be ~ $130 shipped. Hope it fits well.

Click to expand...

Nice. Could you let me know what you think of everything when your finished? Going to be a bit before I get to mine. Waiting for the CEL to come back at the moment. I put a new MAP Sensor rubber elbow on mine awhile back. The vacuum reading looked a little funny to me on the freeze frame info. This was after about 600 miles when I saw that one of my rear exhaust manifold bolts was backed out about a 1/4". Was really hoping that was the problem. But the CEL came back. Thinking it was about 200 miles ago since I did the rubber elbow. Do not drive much so it takes time.

Here's a follow-up to my installation of the Walker Pre-Cat and Rugged Ridge Headers.

http://www.naxja.org/forum/showthread.php?p=246331649#post246331649

Saw your write up before I saw this. Didn't realize it was you when I answered. I am not to bright sometimes. Still waiting for CEL to come back on after replacing the MAP Sensor Elbow I told you about. Been about 450 miles now. I know it will come back on. I am not that lucky.

Good luck... I tried replacing several sensors and items but my P0432 kept coming back. The only thing I didn't replace before replacing the header and pre-cat (recently) was the Upstream O2 Sensors. I doubt that would've made any different w/the P0432 code but who knows. I also started having a Cylinder 6 Misfire code and some slight stumbling that seems to have been fixed w/the Pre-Cat and Header swap. Of course it's only been about 20-30 miles so we'll see.