[f3ar13]

i have checked, replaced or cleaned
IAC valve
throttle body and gasket
PCV valve and hose
all vacuum hoses
TPS sensor
spark plugs and wires
ignition coil
fuel filter and pump
sprayed ether around the intake manifold gaskets (but not SURE if its good because the idle always lopes and i cant tell)
sea foamed the fuel injectors
cleaned MAF sensor
changed air filter

and my 99 escort has a rough idle, the engine lopes, shitty acceleration, has a light ticking noise and randomly gives me a check engine code P1131. i know all about the dropping valve seat thing and thats why i want to just get a rebuilt head with new valve seats but if it could be something else i would like to try that.

before i just buy a rebuilt head is there ANYTHING else it could be before i spend the 280$ like timing, valve seals any sensors etc i just want to know everything that could be making this car run like crap

 

[skaterbro]

P1131, have you looked over the wiring to the upstream o2 sensor yet? Or check for cracks or leaks from the exhaust manifold or gasket? If the wiring checks out and the exhaust looks okay i'd say go ahead and replace the upstream sensor.

As for the ticking, that could very well be a seat on it's way out. You could do a leakdown test on the head to see if that is the case. Luckily removing the head on these things is not hard at all. Like two hours if you don't know what you're doing, half that if you do.

 

[f3ar13]

well i just checked the o2 sensor. looked good but i got a new one...put it in, didnt do anything.

about how mush is a leakdown test? and if it failes the test will i know what is wrong with it or will it just narrow down whats wrong

 

[skaterbro]

You replaced the upstream o2 sensor and cleared the code but the p1131 came back? And the exhaust manifold and gasket? How are they?

I've never paid anyone to do leakdowns so i couldn't help you with prices, but it shouldn't be much. The tools used are nothing special and it isn't hard to do. It will tell you if the seats are sealing the way they should be.

I'd pull the head and see what's going on. You could easily get it done over a weekend. Plus it will give you a chance to really inspect the exhaust manifold for cracks.

 

[f3ar13]

yea i replaced the o2 sensor in the exhaust manifold, checked for leaks and cracks but it all looks good, just seems the car is running to lean as the code came back after about 90 miles of driving

i will lookup how to do a leakdown test then and see what happens. im just so sure at this point its something in the head.

 

[EscortLX97]

How it does with out the MAF sensor disconnected I once had that lean code and turn out to be the MAF. disconnect with car not running then start it an see how it goes.

 

[f3ar13]

will do, what "should" happen when i disconnect it, and what shouldn't it do so i know if it is a problem. i will disconnect it when i get home

 

[EscortLX97]

With it disconnected it will make the fuel mix richer at low RPMs, with the car running and at operating temp the O2 will take over the control of the mix.

 

[f3ar13]

i unpluged the MAF sensor and the car just got worse. it would almost die, then be ok, then almost die etc it made the loping worse. the o2 sensor is new so i know its not the prob.