Here’s the whole long story. Check engine light has been on for months. I thought it was MAF sensor. Inspection was due so I cleaned it thinking it would shut off the light…nope. Took it to auto zone to get codes read. I had 3 codes. Two EVAP codes and a fuel sending unit code. The fuel sending unit ended up being covered by warranty after much arguing with the service manager. That takes me to the EVAP codes. Everything I read online pointed to dirty EGR valve. Yesterday I took it off and cleaned it even thought the mechanic here said it didn’t look too dirty. In addition to the EGR valve I wanted to clean the throttle body. Now I think this is where I fucked up. I was moving the throttle body manually. I cleared the codes and started my truck; it was running a little weird. Took it to AutoZone again and 12 codes!!! Oh Crap!! Now I was hoping that I loosened up a bunch of crap and it just needed to be worked threw. Cleared codes again last night. Took it to the deal this morning and 9 codes (getting better). They told me that the rear wiring harness in corroded and that’s what’s setting off the EVAP codes (that takes care of the original problem) hopefully the wiring harness is what is setting off the abs light also ($367). IN ADDITION to the 2 original issues I caused more codes last night and now the accelerator position sensor is setting off codes and the dealer says it needs to be replaced ($269 parts and labor) and the ion sensing module is setting off codes and needs to be replaced $278 parts and labor. I’m hoping those problems will just go away after a while. I need more info on the wiring so I can fix it myself. anyone experience any of these symtoms when doing an EGR cleaning? btw 2000 rodeo. i love this truck but right now i want to kill the thing :mad:

umm wow! that is a lot of codes!

Yank the neg, battery cable for 15 minutes. Replace and then see what you have. The first time, I cleaned my EGR and trottle body, I had a flashing CEL after I put it back together and started. It ran ruff due to the carb cleaner getting into the engine while cleaning the TB (it wasn't running when I did this). It ran ruff for about 1 minute and smoothed out, but the flashing CEL was there. I have no idea how many codes I had. After I turned it off, and started it again the CEL was gone.

I would reset it again, and drive it. If you have a solid CEL, fine. Give it a couple days, reset again and then head to AutoZone. When the CEL goes off it does for a reason. Sometimes it is a fluke (emission). And the parts you mentioned, I think can be tested to see if they are ok (which I bet they are). You just don't start, tossing new parts, at it based on codes (unless, the truck runs like poop, and the code doesn't go away).

Best of luck!
-Ryan

umm wow! that is a lot of codes!

Yank the neg, battery cable for 15 minutes. Replace and then see what you have. The first time, I cleaned my EGR and trottle body, I had a flashing CEL after I put it back together and started. It ran ruff due to the carb cleaner getting into the engine while cleaning the TB (it wasn't running when I did this). It ran ruff for about 1 minute and smoothed out, but the flashing CEL was there. I have no idea how many codes I had. After I turned it off, and started it again the CEL was gone.

Hey Ryan, if I remember your CEL light EGR cleaning story, didn't you also have to tighten the gas capper dealer's suggestion to correct the problem? Just an FYI if I'm correct :2cents:

If the wiring harness is corroded, then clean it yourself and put di-electric grease to prevent rust and corrosion on those wire ends.

Re-check the battery cables and the ground cables.
I would re-check all the wire connectors and make sure they are plugged in tight.

You can bring the vehicle to Autozone to get the codes scanned FREE.

Have your alternator checked as the alternator starts failing then it will set OFF diffirent error codes including the ABS.

umm wow! that is a lot of codes!

Yank the neg, battery cable for 15 minutes. Replace and then see what you have. The first time, I cleaned my EGR and trottle body, I had a flashing CEL after I put it back together and started. It ran ruff due to the carb cleaner getting into the engine while cleaning the TB (it wasn't running when I did this). It ran ruff for about 1 minute and smoothed out, but the flashing CEL was there. I have no idea how many codes I had. After I turned it off, and started it again the CEL was gone.

I would reset it again, and drive it. If you have a solid CEL, fine. Give it a couple days, reset again and then head to AutoZone. When the CEL goes off it does for a reason. Sometimes it is a fluke (emission). And the parts you mentioned, I think can be tested to see if they are ok (which I bet they are). You just don't start, tossing new parts, at it based on codes (unless, the truck runs like poop, and the code doesn't go away).

Best of luck!
-Ryan


i know, i don't want to start throwing new parts on until the dealer proves to me that they are broken! i don't trust this deal at all, but its the only one around

Aaron, the EGR system wont have anything to do with the EVAP codes. They are both totally separate systems. Try to get the exact codes you are getting & post them here. I don't buy the bad harness thing. The EVAP cannister & harness is under the (under mounted) spare tire on 1998-2004 rodeos. Pull the electrical plugs, clean & reinsert to see if that helps. As far as the ion sensing system, are you running denso spark plugs? You need to with this system.
G/luck
Joel

rodeo is correct again do not go replacing oarts just yet
by moving throttle manually when cleaning the t-body it is normal for at least 5 codes to set if the ignition was on I am under the assumption that you had the vehicle running if so that could have also caused misfire codes and Ion module codes these Ion modules rarely give out as for the abs light likely cause is one of the front wheel speed sensors
what is your EVAP dtc

Here are the codes and the recommended solution from the dealer:

P0440
P0447

These are from corroded wiring. This kind of makes sense because I live in buffalo, NY and everything rusts and corrodes because of al the salt on the roads

P0463 – Fuel sending unit – covered by warranty but the dealer but doesn’t want to do this until the wiring harness is replaced because they do not want to cause further damage to the wiring harness.

P1125
P1295
P1299
P1515

Accel. Position sensor should be replaced

P1320
P1326

Replace Ion sensing module should be replaced.

I get parts from the dealer at wholesale cost, so when I get some cash I’m going to replace the wiring harness myself ($103) and then take it in to get the fuel sending unit done. Hopefully by then the other problems will have worked themselves out LOL. Otherwise I’ll replace those things myself. I'm not sure who it was but a guy at the dealer who was not the mechanic and not the service manager (who i dislike) was extremely helpfull in getting me a copy of the mechanics diagnostic and the part numbers for the parts that need to be replaced. he even tried to get me a discount on the parts befor i told him i had a wholesale account there. I'm still srewed though. the inspection is overdue and i have no $$ to fix the truck right now so i can't get the CEL off to get an inspecion. I don't think i'll be driving for a couple weeks. luckily i'll be in columbus, OH all next week on business.

Aaron, the EGR system wont have anything to do with the EVAP codes. They are both totally separate systems. Try to get the exact codes you are getting & post them here. I don't buy the bad harness thing. The EVAP cannister & harness is under the (under mounted) spare tire on 1998-2004 rodeos. Pull the electrical plugs, clean & reinsert to see if that helps. As far as the ion sensing system, are you running denso spark plugs? You need to with this system.
G/luck
Joel

I will be inspecting the wiring befor i replace any wiring to see how bad it really is. my spare is on the back of the truck, where would the cannister and harness be? the plugs have never been changed.

umm wow! that is a lot of codes!

Yank the neg, battery cable for 15 minutes. Replace and then see what you have. The first time, I cleaned my EGR and trottle body, I had a flashing CEL after I put it back together and started. It ran ruff due to the carb cleaner getting into the engine while cleaning the TB (it wasn't running when I did this). It ran ruff for about 1 minute and smoothed out, but the flashing CEL was there. I have no idea how many codes I had. After I turned it off, and started it again the CEL was gone.

I would reset it again, and drive it. If you have a solid CEL, fine. Give it a couple days, reset again and then head to AutoZone. When the CEL goes off it does for a reason. Sometimes it is a fluke (emission). And the parts you mentioned, I think can be tested to see if they are ok (which I bet they are). You just don't start, tossing new parts, at it based on codes (unless, the truck runs like poop, and the code doesn't go away).

Best of luck!
-Ryan

I'm going to give it another day or two then take it to auto zone to see what codes has. i will postthem when i get them. the truck runs perfect! i feel nothing wrong with. it idel's at 850 and goes up to 1000 when a/c compressor kicks on.

rodeo is correct again do not go replacing oarts just yet
by moving throttle manually when cleaning the t-body it is normal for at least 5 codes to set if the ignition was on I am under the assumption that you had the vehicle running if so that could have also caused misfire codes and Ion module codes these Ion modules rarely give out as for the abs light likely cause is one of the front wheel speed sensors
what is your EVAP dtc

I have a different size spare on the rear left right now that seemed to Coincide with the ABS light going on. 2 weeks befor i put the spare on i had to stop really fast and the ABS was acting up without the ABS ligh going on. it would kick on when i was at really slow speeds coming to a stop (5mph) i'm not sure whats going on there but is has done this periodically since i bought the truck new, it usually ment i needed breaks but the front is new pads and rotors. the rear was done less than 20,000 miles ago (new pads and rotors). they should be ok

Aaron, diff sized tires can definately cause ABS issues. ABS (and 4x4) needs tires EXACTLY the same diameter. That might be your ABS problem. Your EVAP system will still be under the back of the truck. It's a fairly large square black box. Are you dealing with Towne Isuzu? They've been pretty good to me (and my family) in the past. I'm in WNY as well :uhoh: .
G/luck
Joel

Aaron, diff sized tires can definately cause ABS issues. ABS (and 4x4) needs tires EXACTLY the same diameter. That might be your ABS problem. Your EVAP system will still be under the back of the truck. It's a fairly large square black box. Are you dealing with Towne Isuzu? They've been pretty good to me (and my family) in the past. I'm in WNY as well :uhoh: .
G/luck
Joel

hey Joel, thanks for the info about the ABS and 4x4 issues (never wants to come out of 4wd). thaks for the EVAP box location. yes i'm dealing with town isuzu, they are good mechanics but the servise manager does like to listen to me. especially this last time when i told him that the fuel sending unit was cover by power train warrenty and he kept insisting it was not, even after i offered to give him the phone number and extension of the person i talked to at the main isuzu office who told me it was. he finally spoke with the warrenty person at town isuzu and decided i was correct. how'd you like that snow yesterday? i spent some time in the southtowns doing a little off roading in all the fresh snow. i had a great time. thanks for all the help.

Yeah, The isuzu service mngr (Kirk) can be a real D, but like you did, if you keep cool with him & throw a bone their way (have them do your yearly NYS inspections, let them do simple serivce stuff), they will take care of you. I'm ALL too familiar with winter time *off roading* in the S.towns. I live in West Falls.

G/luck
Joel